Serology: It’s in the Blood by Katherine Ramsland 1
http://www.crimelibrary.com/criminal_mind/forensics/serology/1.html
The "Fatal Vision" Murders
February 17, 1970. It was
one of the worst crime scenes that the
Colette, MacDonald's
twenty-six-year-old pregnant wife, had been stabbed numerous times in the
chest, and she lay bleeding underneath a torn blue pajama top that apparently
had been worn by him. Above them both, written in blood on the headboard of the
bed, was the word Pig, which was reminiscent of the vicious Manson
murders in
Down the hall in one
bedroom was two-year-old Kristen. She had been stabbed thirty-three times in
the chest and back, and her sister, five-year-old Kimberly, had been repeatedly
stabbed and hit. Both were dead, and next to Kristen was a pool of blood near
which a bloody footprint was visible.
MacDonald's wounds were
relatively minor (though he later claimed he'd been stabbed twenty-three times)
and as police searched the house he told them what he could remember of the
blitz attack. According to him, he'd been sleeping on the living room couch
when Colette's cries woke him. Three men and a woman were standing in the living
room, dressed like hippies and chanting, "Acid is groovykill the
pigs." MacDonald said that he then tried to fight them, but they slashed
him with an ice pick. In the process, he'd torn his pajama top and had then
wrapped it around his hand to buffer the blows. Eventually the intruders
knocked him unconscious with a baseball bat. When he came to, he found his wife
and daughters bleeding from wounds and unresponsive to his attempts to revive
them. He then made the emergency call that brought the MPs to his door.
Detectives William Ivory
and Franz Grebner made a thorough investigation of the crime scene and
determined that MacDonald's story just didn't add up. The relatively minor
disorder in the living room failed to support the description of a struggle
between MacDonald and four other people. Even more suspicious to them was the
fact that one of the magazines on the table had extensive coverage of the
Manson murders, which bore obvious parallels to this incident. The whole thing
was beginning to look staged. To the detectives' minds, it raised questions
about why this gang of hippies on acid who'd stabbed MacDonald's family in such
a frenzy had allowed him to survive relatively unscathed, with some slight stab
wounds and a few bruises.
It was also troubling that
MacDonald, who had terrible eyesight without his glasses, had been able to give
such detailed descriptions of the perpetrators in his home. And why had he
dialed the phone in the dark? When the MPs arrived, the house was dark.
Then more evidence began to
put MacDonald into a more suspicious light. On the bed where Colette had been
attacked was the torn finger from a latex glove such as surgeons wear, and a
knife that MacDonald claimed to have pulled out of his wife was clean of
fingerprints. It also proved not to be the knife that had stabbed her. Also
free of prints were both of the phones that MacDonald said he'd used to call
for help. Even more troubling was the fact that several blue threads from the
pajama top were found beneath Colette, although MacDonald had claimed to have
simply laid the garment on top of her. Quite a few fibers were discovered below
the headboard of the bed where "PIG" had been written by a
right-handed person wearing something that resembled a glove. More fibers were
found on a bloodstained piece of wood found in the back yard. Out there, they
also found an ice pick and another knife, both wiped clean. Then more blue
threads turned up in the children's bedrooms, including one under Kristen's
fingernail, but none were found in the room where MacDonald claimed he was
sleeping, and where the jacket had supposedly been torn.
The most damning evidence
was the blood pattern analysis. Each family member had a different blood group,
which made it possible to track where they had been. MacDonald's blood showed
up in the kitchen next to a cabinet that contained surgical gloves. It was also
in the bathroom, but there was none in the living room where he'd claimed to
have been stabbed, except for a tiny smear on a magazine, nor in the hall where
he's said that he'd lain unconscious. A footprint in Kristen's bedroom was made
with Colette's blood. Blood spatters on the ceiling indicated that a club had
been raised back with force after hitting Colette.
Added to this was the
lack of evidence that four intruders had not only entered the house but had
struggled with all of the victims. This scenario is close to impossible.
Nevertheless, when it was
found that the evidence had been mishandled and some of it lost, the charges
were dropped. Then the investigation came alive again.
One of the initial FBI
analysts, Paul Stombaugh, had determined that Colette had been covered with a
sheet and moved by someone wearing the blue pajama top. He also examined
MacDonald's pajama top and observed that all forty-eight holes made by the ice
pick had smooth edges and a round shape. He believed that this could only have
occurred if the garment had been stationary. It would not have happened if the
scenario were as MacDonald described it—that he'd wrapped his jacket around his
hand to ward off blows. (A demonstration showed that an ice pick stabbed at a
moving target would make jagged edges.)
Then Stombaugh noted two
bloodstains from Colette on two parts of the torn jacket, and when they were
held together, they matched, which meant the stain had been made before the
jacket was torn. So MacDonald had not placed it on her after he found her lying
dead on the floor, but had gotten her blood on himself before the shirt was
torn.
Stombaugh then folded the
jacket to see how the stab marks matched and was able to show that the
forty-eight punctures could have been made by twenty-one thrusts of the pick,
which matched the number of stab wounds found on Colette's body.
This startling evidence
helped the prosecution to win one first-degree and two second-degree murder
convictions against Jeffrey MacDonald, and he is currently serving three
consecutive life terms.
However, that was not the
end of it. The evidence has been questioned backwards and forwards by those who
believe that the MacDonald investigation was shoddy, and problems have emerged.
The defense had pointed
out that Paul Stombaugh had little experience with blood analysis, but the jury
had not heard this challenge to his credibility. Also, the defense had not been
allowed to examine the bloody pajama top to make their own analysis of the
bloodstains. On visual inspection, they did not buy Stombaugh's ideas, and
years later they discovered that another lab technician had come to a different
conclusion about the torn shirt: She thought the shirt had been stained after
it was torn. (Nevertheless, all of this was vigorously debated at trial.)
It was also proven that
although Stombaugh claimed that he'd folded the pajama top in a manner that
matched how it was found at the crime scene, in fact the photos of the scene
did not match the photos of his own experiments. He'd had to change the
position of the shirt to get the holes to line up as he thought they should. It
was also pointed out that the garment would not stay so neatly lined up as the
pick was being used to make one stab wound after another. The experiment also
failed to account for the punctures in Colette's own pajama top, which was
between her wounded chest and the jacket that her husband had laid on her.
Even so, another
prominent blood pattern analyst, Judith Bunker, had declined to serve on the
defense, because she felt that her conclusions would not support their
position.
To understand how
bloodstains at a crime scene can be open to debate, it's instructive to see
where forensic blood analysis got its start.
The Mad Carpenter
It was the brutal murder
and dismembering of two young boys on the
Earlier that day, Tessnow
had been seen talking to them, and although he denied any involvement, a search
of his home turned up recently-laundered clothing that had suspicious
stains. He claimed that they were from wood dye, which he used almost daily
in his profession. Unable to prove otherwise or to find other
incriminating evidence, the police left him alone...until one investigator
recalled a similar crime.
Three years earlier in
The local prosecutor then
heard a farmer's report that a man who looked like Tessnow was seen fleeing
from his field, and he then found seven of his sheep slaughtered. Their
legs had been severed and tossed about the field. Tessnow was brought in
for a line-up and the farmer had no trouble picking him out as the man who had
run from his field.
Still, the police needed
better evidence to tie Tessnow to the murders. Then they heard about a
test recently developed by a biologist, Paul Uhlenhuth, that could distinguish
blood from other substances, as well as mark the difference between human and
animal blood. Tessnow's clothing was given to Uhlenhuth for thorough
examination and his conclusions marked a turning point in the history of
forensic science. He found dye, but he also detected traces of both sheep
and human blood.
With this evidence,
Tessnow was charged, tried, convicted, and executed.
Shortly thereafter,
forensic blood analysis began to progress rather rapidly in several directions.
Serology
The analysis of the
properties and effects of serums (blood, semen, saliva, sweat, or fecal matter)
is called serology. We'll concentrate here on the principal tests used to
identify blood. According to Henry C. Lee, a forensics expert who has
assisted law enforcement in over 6,000 major criminal investigations—including
that of O. J. Simpson---blood evidence is found most often in "crimes of
violence such as homicide, assault, and sexual assault." It may be
in the form of fresh liquid, coagulated, dried, or as a small drop or stain,
and each form involves a different method of preservation and collection.
We all have about ten
pints of blood getting pumped throughout our bodies. When wounded, bodies
leak or spray blood, and the behavior of blood in flight tends to be unaffected
by such things as temperature, humidity, or atmospheric pressure. In
other words, it's uniform.
Despite how well the
crime scene may get cleaned up, even the finest trace of blood can often be
detected and further tested. It is often the case that while the
perpetrator may scrub down the obvious places, he can still miss between
floorboards, under pipes, and inside drains. Merely by pouring water on
some tiles at a murder scene and pulling them up wherever the water flowed
beneath them, one detective found the only existing trace of the crime--blood.
His discovery so surprised the killer, who felt certain he'd done a through job
of cleaning up, that he instantly confessed.
Different blood types
were recognized in 1875, but it wasn't until 1901 that Karl Landsteiner named
and standardized the groups. Red blood cells carry a substance called an
antigen, which produces antibodies to fight infection, and there appeared to
Landsteiner to be several different types. In a centrifuge, he separated
the red blood cells from the plasma or watery serum in which they are carried
through the body. Then adding red blood cells from various other
subjects, he found two distinct reactions—clumping and repelling. He
labeled them types A (antigen A present, anti-B antibody present, but antigen B
absent) and B (antigen B present, antigen A absent). Then a third
reaction was labeled C (both antigens A and B absent), but was relabeled later
as O. Then another type of serum was discovered, and this fourth type was
labeled AB (both antigens present). It soon became clear that the blood
type depended on genetic inheritance from parents, which helped with paternity
tests. Type A and O are the most common in the human population, with AB
the most rare.
Then Dr. Leon Lattes in
In 1940, Landsteiner also
discovered the rhesus factor in blood, labeling it Rh+ if the antigen was
present in the red blood cells and Rh- if not. Today, blood typing also
includes different types of enzymes and proteins that perform specific
activities in the body, which helps to individualize the blood. (More
than 150 serum proteins and 250 cellular enzymes have been isolated, as well as
many more antigens.)
Nine years went by before
British scientists came to the conclusion that the nuclei of female blood cells
contain a chromosome-related structure that set them apart from those of males,
and they named this the Barr Body. It added one more dimension to
identification via blood samples.
When a darkish substance
is found at a crime scene, it must first be determined to be blood. There
are several tests—presumptive tests used strictly for screening---that will
differentiate between blood and other substances, but if other chemicals are
present at the scene to which the test chemicals are sensitive, the tests may
be vulnerable to corruption. For that reason, these tests are done with
great care. A positive result from any of them is an indication to go
ahead and use other tests to confirm.
Before doing anything,
the crime scene investigators must take some precautions in order to avoid both
biohazard to themselves and sample corruption. In his Physical
Evidence in Forensic Science, Henry Lee suggests the following:
Presumptive tests:
The first test is simply
the use of a powerful light moved across every surface of a crime scene.
That yields possible traces for visual inspection.
If nothing is seen, but
there is reason to suspect blood had been present, a chemical called luminol is
sprayed across the scene because it reacts to blood by making it
luminescent. It only takes about five seconds. The procedure
requires that the room be considerably darkened in order to see the faint
bluish glow, and the intensity of the glow increases proportionately to the
amount of blood present. It works even with old blood or diluted stains,
and can illuminate smear marks where blood has been wiped away. However,
there is one problem with this test: luminol can destroy the properties of the
blood that investigators need for further testing. Its use is limited to
proving that blood is present even if not visible.
The Kastle-Meyer Color
Test uses a solution of phenolphthalein and hydrogen peroxide on a piece of
filter paper, and when blood of any quantity is present, it turns pink.
However, it also turns pink in the presence of potatoes or horseradish, so care
must be taken at the scene.
Sometimes
microcrystalline tests are also performed. The two most often used are
the Takayama and Teichmann tests. Both add specific chemicals to the
blood to make it form crystals with hemoglobin derivatives. These tests
are also sensitive to other materials that may be present in a
bloodstain.
Further testing:
From there, investigators
use the precipitin test to determine whether the blood is of animal or human
origin. German biologist Paul Uhlenhuth discovered that if he injected
protein from a chicken egg into a rabbit, and then mixed serum from the rabbit
with egg white, the egg proteins separated from the liquid to form a cloudy
substance known as precipitin. In other words, it forms an
antibody. In the forensic test for human blood, either a sample of the
suspect blood is put into a test tube over the rabbit serum or it's used in the
"gel diffusion" test, where it's placed in gel on a glass slide next
to a sample of the reagent (anti-human serum). Passing an electric
current through the glass, the protein molecules filter into the gelatin and
toward each other. If a line forms where they meet---called a precipitin
line---that means the sample is human blood.
After that, analysts can
go ahead and determine blood type with an ABO test, and then work on the gender
of the person from whom the blood came. To get a more thorough
enzyme/protein profile, they use electrophoresis (a blood-soaked piece of
cotton placed in gelatin on a slide and submitted to electric current).
In 1925, another
blood-related discovery important to criminal investigation was made.
Around 80 percent of the human population were found to be
"secretors," which means that the specific types of antigens,
proteins, antibodies, and enzyme characteristic of their blood can be found in
other bodily fluids and tissues. In the case of a secretor, investigators
can tell the blood type by examining the saliva, teardrops, skin tissue, urine,
or semen. In a rape case, for example, where the perpetrator is a secretor,
potential suspects can be narrowed down through blood type analysis.
These days, thanks to
discoveries in 1985, DNA technology has replaced the tests for specific enzymes
and proteins. It's more accurate to match DNA from a blood sample at a
crime scene to a source than to draw up an entire blood profile.
Yet blood at a crime
scene can offer even more clues than gender and type. Aside from the mere
presence of blood, the different ways that blood lands on a surface has given
rise to a forensic subspecialty known as blood-pattern analysis, or BPA.
Let's hear about that from one of the experts.
Blood Pattern Analysis
Blood pattern analysis
plays an important role in the reconstruction of many crime scenes. For
example, when a prominent
Blood may be dripped out,
sprayed from an artery, oozed out through a large wound, or flung off a weapon
raised to strike another blow. In the 1930s, Scottish pathologist John
Glaister classified blood splashes into six distinct types:
Trails, either in form of
smears when a bleeding body is dragged, or in droplets when it is carried.
(Trails also form when a person is wounded and walks away but leaves blood along
the way.)
Any of these can be
traced back to their converging point by considering such factors as the
surface on which it fell, the angle it hit, and the distance it traveled.
Brian Kennedy, a sergeant
with the Sacramento County Sheriff's Department in
"Bloodstain
patterns," Kennedy says, "will help the investigators understand the
positions and the means by which the victim and suspect moved, interacted, and
struggled through the crime scene. With an understanding of what and how things
occurred, investigators can focus and find fingerprints, footprints, hairs,
fibers and other forms of trace evidence. The assessment of bloodstain patterns
will also limit the need to collect an overabundance of redundant blood sample
for DNA. Furthermore, a reconstruction of the scene helps the investigators
determine which of the witnesses and suspects is telling the truth or
lying."
The shape of the blood
drop itself, according to Kennedy, can reveal significant information.
"The proportions of the drops can reveal the energy needed to disburse it
in those dimensions. The shape of the stain can illustrate the direction
in which it was traveling and angle at which it struck the surface.
Choosing several stains, and using basic trigonometric functions, enables us to
do a three dimensional recreation of the area of origin from which a
blood-letting event occurred."
Kennedy goes on to point
out that the disruption of a blood drop on impact with a surface is directly
related to the texture of the surface. "A smooth surface, such as
glass,
will provide the recording of a stain with clean edges and shapes of proper
geometric proportion. A rough surface, like concrete, will break the
surface tension irregularly and generate a star burst, or spinning
effect. An experienced analyst is able to use some of the most disrupted
stains to recreate the event. Arterial spurts, for example, when compared
with the anatomical location of the injury may provide information about the
position when the injury was inflicted and any subsequent movement by the
injured party. Castoff patterns, or drops that are thrown off of a
swinging instrument in the arc of the swing, can illustrate the position of the
assailant when swinging a knife, or club."
Other crime scene analysts make the analysis of blood drops and spatters a bit
more standard, but are aware, like Kennedy, that the surface type has a
significant effect on just how the blood will appear. Distance estimates
such as those provided in the following list are of little value unless the
effects of a surface are known.
According to the basic
teaching texts, the shape of a blood drop can reveal a lot about the conditions
in which it fell. Given the many variations in what can happen at a crime
scene, the experts don't necessarily all agree, but a flexible rule of thumb
with a generally smooth and non-porous surface might be the following:
It must be emphasized
that blood pattern analysis is a complicated discipline and requires experience
with many different situations to learn to do an accurate reading. While
any of the above statements may be true, there can also be exceptions, and all
interpretations are contingent on the factors that make up the context of the
crime scene, most specifically the surface on which the blood made an impact.
"All classifications
of bloodstain patterns help in the reconstruction of the events," Kennedy
points out. "Spatter patterns give the nature of the force and positioning
of the victim when shot or bludgeoned. Castoff patterns reveal the
positioning and the possible size of the assailant. One also gets an
indication of the size of the instrument swung and whether the swinger is left-
or right-handed. Transfer patterns and hemorrhage or drip patterns give
the direction of movement after blood is shed and can give an indication of
timeframes. Arterial spurting can give the position, movement and seriousness
of the injury, while 'shadows'---the absence of blood where one would expect to
find it---suggest movement or removal of objects and changes to the
scene."
A case in
"I have worked many
cases in which bloodstain patterns contributed significantly to a guilty plea
or guilty verdict," Kennedy recalls. "I have also worked cases in
which the bloodstains did not support the initial allegations and the defendant
was convicted of a lesser crime, or the charges were dismissed. For
example in People vs. Brett Brooks Harris in
In another case on which
Kennedy worked, People vs. Pallermo in
Asked about current
research that may provide breakthroughs for forensic investigation, Kennedy
said, "Bloodstain pattern analysis involves a constant need for research
and development. The more cases that are worked and the more
investigators involved, the more sophisticated the discipline will become.
Probably the most advanced research has been done by members of the Crime Scene
Bloodstain Section of the Royal Canadian Mount Police, Forensic Support
Services. The RCMP is the only agency I know in the world that assigns and
trains experienced crime scene investigators to do bloodstain pattern analysis
only. They have developed a number of protocols that have been adopted around
the world. Dr. Fred Carter, a professor of physics, has worked with the
RCMP to develop several computer programs to teach the new analyst and help the
experienced investigator."
No matter what kind of
analysis is used on the blood at a crime scene, care must be taken to handle it
properly and to prevent putrefaction. Photos and notes should be taken
before any blood is lifted. Samples should not be exposed to heat,
moisture, or bacterial contamination, because this shortens the survival time
of proteins, enzymes, and antigens. Delays in getting samples to the lab
must be avoided at all cost, because it can diminish evidential value.
This was
one of the central issues in the most prominent case of the past decade in
which blood analysis was a primary feature: the O. J. Simpson investigation.
Blood Trails, DNA and O.J.
Since 1985, with Alec
Jeffrey's discovery of the uniqueness of portions of the DNA structure of
certain genes, investigations involving blood have taken an entirely new
turn. While the ultimate goal of the analysis of proteins and enzymes was
to individualize blood, that's pretty much established with DNA
technology. Within a year of the discovery, DNA typing was being put to
the test in criminal cases. It not only cleared one man who had confessed
to a crime, but also led to the conviction of the actual killer in the same
crime.
DNA can narrow down
suspects in a hurry, but it's not fool-proof. It can be challenged in
court on the basis of sloppy evidence collection and the corruption of samples
during testing. That was the tactic that O. J. Simpson's defense team
used to win for him an acquittal in his double murder trial. Just how did
they manage to accomplish this? To trace their strategy, let's look at
the case.
On the night of July 12,
1994, Nicole Brown Simpson and Ronald Goldman were slaughtered outside her
Brentwood,
When Simpson returned to
Then when several
droplets of blood at the scene failed to show a match with either of the
victim's blood types, Simpson's blood was drawn for testing (after the
droplets had already been collected). Comparison between his DNA and that
of the blood at the scene showed strong similarities. The tests indicated that
the drops had three factors in common with Simpson's blood and only one person
in 57 billion could produce an equivalent match. In addition, the blood
was found near footprints made by a rare and expensive type of shoe—shoes that
O. J. wore and that proved to be his size.
|
Ronald Goldman |
Next to the bodies was a
bloodstained black leather glove that bore traces of fiber from Goldman's
jeans. The glove's mate, stained with blood that matched Simpson's, was
found on his property. There were also traces of the blood of both
victims lifted from inside Simpson's car and house, along with blood that
contained his DNA. In fact, his blood and Goldman's were found together on
the car's console.
Forensic serologists at
the California Department of Justice, along with a private contractor, did the
DNA testing. Then other evidence emerged, such as the testimony of the
limousine driver who came to pick Simpson up for the ride to the airport: On
the night of the murder, while he waited for Simpson, he had seen a black man
cross the driveway and go into the house. Then Simpson claimed that the driver
had been unable to get him on the intercom because he had
"overslept." So then who was the black man who had entered the
house?
When arraigned, Simpson
pleaded Not Guilty and hired a defense team of celebrity lawyers. Barry
Scheck and Peter Neufeld from
The reliability of this
evidence came to be called the "DNA Wars," and three different crime
labs performed the analysis. All three determined that the DNA in the
drops of blood at the scene matched Simpson's. It was a 1 in 170 million
match, using one type of analysis known as RFLP, and 1 in 240 million match
using the PCR test.
Nevertheless, criminologist
Dr. Henry Lee testified that there appeared to be something wrong with the way
the blood was packaged, leading the defense to propose that the multiple
samples had been switched. They also claimed that the blood had been severely
degraded by being stored in a lab truck, but the prosecution's DNA expert,
Harlan Levy, said that the degradation would not have been sufficient to
prevent accurate DNA analysis. He also pointed out that control samples
were used that would have shown any such contamination, but Scheck suggested
that the control samples had been mishandled by the lab—all five of them---and
the jury bought it.
The evidence was damning,
but the defense team managed to refocus the jury's attention on the corruption
in the Los Angeles Police Department. They then disputed the good
reputation of the forensics labs, insisting that the evidence had been
carelessly handled. Deliberating less than four hours, the jury freed
Simpson with a Not Guilty verdict. They simply failed to understand how damning
the DNA evidence really was and how ill-fitting was the defense's logic about
certain aspects of the blood at the crime scene.
Nevertheless, it can
certainly be the case that what appears to be overwhelming blood analysis
evidence still fails to tell the whole story. We can see that in the next
case, a family tragedy that happened in
Analysis Gone Wrong
It should be kept in mind
that analysis always involves interpretation. In the case below, an
interpretation of the bloodstain evidence helped to convict a woman and stood
up to two appeals, but turned out to have been in error.
In
One evening, according to
Lindy and Michael, they were preparing dinner at the camp barbecue site when
they heard a sudden sharp cry from the tent in which Azaria was sleeping.
Lindy went to check and saw a dingo, or wild dog, backing out, shaking
something large in its jaws. It ran away and that's when Lindy discovered
that Azaria was gone. The dog had taken her!
Trackers searched the
area to no avail. There was no sign of the missing baby or the dingo,
except for footprints leading to the road and beyond. The parents grieved
deeply, but eventually accepted their fate as the will of God. They
assumed she was dead.
Eight days later a hiker
discovered baby Azaria's clothing in a crumpled heap west of Ayer's Rock.
Only the baby's jacket was missing, but oddly, her undershirt was inside out
and the booties were neatly laced up inside the jumpsuit. On the neck of
the jumpsuit and undershirt were bloodstains that were later thought to be
consistent with the type of stain that would result from a knife cut, not a
bite. There were also no tooth marks on the clothing.
Around the scene,
investigators found no sign of human remains, no dog hair, and no indication
that violence had occurred between an animal and a baby. No dingo saliva
was found on the clothing. Investigators did some experiments with caged
dingoes and concluded that whatever had happened to the child had not involved
a wild dog. That left human involvement---someone who left the child's
clothing several miles from where she was taken. Suspicion turned to the
parents, and then more specifically to Lindy.
Lest there was doubt
about whether the clothing belonged to the child, blood tests were done to
determine type (no DNA testing was available then), and then compared to the
Chamberlain's blood types. The conclusion was that the clothing had
belonged to Azaria. Another test showed that the undershirt had been worn
the right way when the wound was made, but then someone had removed it, leaving
it inside out. There also appeared to be two bloodstained prints on the
jumpsuit made by the hands of a small adult, like a woman.
A search of the
Chamberlain's car produced what appeared to be the blood of an infant on the
seats and on a pair of scissors in the vehicle. After that, the
Chamberlains were arrested and tried for the murder of their baby
daughter. They insisted they were innocent, but the evidence appeared to
say otherwise. Lindy was convicted of murder and Michael was declared an
accessory to the crime. Lindy went to prison.
On her behalf, many people
began movements to bring out the errors made in the interpretation of
evidence---particularly the experiments done with dingoes and the blood
analysis. The substance found in the car, for example, was not
conclusively proven by any tests to be blood. Nor was the stain on the
T-shirt proven to be from a cut rather than from an arterial bleed. If
the dingo had grabbed the baby by the head or neck, there would be no teeth
marks on the clothing.
Then in 1986, four years
after the trial, Azaria's missing jacket was finally located—partly buried in
sand near a dingo cave not far from the campsite. It was torn and
bloodstained, but in good enough condition to be identified as the one Azaria
wore the last time she was seen. It was sufficient for reasonable doubt
and Lindy was released. The following year, the couple was officially
pardoned. Not long afterward, their convictions were quashed.
No matter how
sophisticated the tests, interpretation is often subject to the narrative that
the investigators build, especially if the evidence is ambiguous. It can
only be hoped that future technology will eliminate the gray areas and provide
more conclusive proof.
Putting It All Together
Several different blood
analysis techniques came together in the Caren Campano case to provide
enough evidence for an arrest. She was missing and there seemed to be
nothing amiss in the home...at first.
Her husband, Chris,
admitted that they'd had a fight just before she had disappeared on July 1,
1992, from their
1. A hema stick
(microcrystal test)
This stick is coated with a blood-sensitive chemical which, when touched to a
substance and then sprayed with distilled water, indicates the presence of
blood. Later in the lab, they determined that it was human blood.
2. Luminol
Although the house appeared to be spotless, when this highly sensitive chemical
was sprayed around the room in the dark, it illuminated so many areas that it
was clear that a virtual bloodbath had taken place.
When blood flies through
the air, the pattern in which it lands can determine its track, as well as the
location and position of the weapon that inflicted the blow. It can also
provide an estimate of how many blows were struck. Investigators found
spatters on the walls, doors, and even across the ceiling. There was also
a blood trail through the house and down the back outside steps. Piecing
together from the splatter patterns what might have occurred, they felt certain
that the victim had received numerous blows to the head with a blunt object,
which collectively would have been fatal.
3. Blood Volume Test
through stain recreation
On the same rug, they poured the amount of blood that would have been needed to
make a stain the same size as the one they found, and then estimated that a
person the size of Caren Campano would have lost at least 40 % of her
blood. She could not have survived that.
4. DNA analysis Reverse
paternity test
Although Caren's father was deceased and they had no samples of her DNA, they
took blood samples from as many members of her family as they could find,
hoping for a partial match with all of them. Finding it, the police had
enough for an arrest on the suspicion of murder.
Finally, a year after her
disappearance, they located Caren's remains, which by this time were mostly
skeletal. The dental records matched and the story told by the many
fractures to the skull confirmed the theoretical scenario pieced together from
the blood spatters in the Campano bedroom. Chris Campano was then
convicted of the murder of his wife.
The various tests used on
blood and blood patterns can offer crucial evidence in the reconstruction of a
crime scene and even the proof of murder without having the body.
New Chapter - Ambiguous Evidence:
Suicide or Murder?
Robert Perry was found
shot to death on March 29, 2001, in a back bedroom of his mobile home in
Kamiah Police Marshal
David Hasz described the scene later in court: The body lay on the floor,
facing the bed. Blood was coming from the back of the frail man's head
and a .22-caliber long-barreled pistol lay near his feet. A deck of
playing cards was scattered on the floor near him. Perry clutched an
oxygen tube in his right hand.
Craig and Carol gave
their statements and seemed quite upset, but the police had doubts when those
statements seemed inconsistent with the crime scene. Their reservations
deepened as the pair altered some details of their stories. Craig indicated
that his uncle had made an earlier comment that he was going to "end
it," and Craig had tried to joke with him about it to dissuade him, saying
he did not want to clean up the mess. They also said they'd found him on
the floor, but then changed that to finding him slumped over on the bed, so
close to the floor they couldn't believe he was still sitting. Carol
indicated that Craig then went to embrace the man, and finding him dead, placed
him on the floor.
Prosecutors believed
Craig Perry shot his uncle, and six months after the incident, Craig Perry was
charged with second-degree murder.
At the trial in June
2004, the background came out. A month before the death, Craig had moved
in to the trailer to care for the ailing man, and a few weeks later, Carol had
joined him. At the time of the incident, both had been in the front
room. Carol said she had heard a loud pop and asked Craig if he had heard
it. After he asked her what she was talking about, they both heard a second one
and rushed to the room.
The defense argued that
Robert killed himself because he was suffering and felt like a burden to his
family. Each side called experts to interpret that evidence, most
specifically the wound pattern and blood spatter evidence.
The bed, complete with
the same bloody sheets, was brought into the courtroom, with the
blood-spattered headboard. Craig Perry's pants were also entered into evidence,
as they bore blood spatter as well.
For the prosecution, Rod
Englert, a blood spatter analyst, reconstructed the event before the jury,
using a stand-in person to represent Robert Perry. He said that the fine
mist of blood on Craig's pants was not a transfer smear from having handled the
body but blowback from the spray released upon impact from a bullet, which
meant that Craig was nearby when Robert was shot. The fact that he had
blood on his pants but none on his shirt seemed to contradict his statement
that he had hugged his uncle when he found him.
In addition, Englert
evaluated the blood on the bed and said that the man could not have been shot
while sitting there with his head slumped, because blood would have hit his
legs, and there was none found in those areas. Blood found on the side of
the bed indicated that Robert had been seated on the floor, leaning on the bed,
when shot. Blood on Robert's hands, Englert said, indicated that it was
impossible that he had shot himself. It seemed instead to have come from
contact with blood on the floor.
However, the pistol was
not tested for fingerprints, and no tests were done for gunshot residue in the
bedroom or on Craig Perry, so important evidence for reconstruction was
lost. (A crime scene processor claimed the lab used did not accept
gunshot residue tests.) Also, no second bullet was recovered from the
scene, though two shell casings were.
Pathologist Dr. Michael
Cihak, who performed the autopsy, demonstrated how the pistol had to have been
held to make the wounds he found on the righthand side of the back of Robert's
head. He seemed to think it was unlikely that anyone would have chosen
that position to shoot himself, and showed how awkward it was.
However, Cihak had
already changed his own findings once, based on reports. He had
located one large bullet fragment and several smaller ones in the skull, and
when he learned that one casing had been found, he said he had one
bullet. But when he later learned that two had been found, he changed
that to say that one bullet alone could not have caused the wound he
found.
Despite his findings, he
admitted on cross-examination that suicide could not be ruled out.
His testimony was echoed
by Dr. Vincent Di Maio, chief medical examiner from
To counter that, the
defense called surgical pathologist George Lindholm, who testified it was
possible for a man to shoot himself twice with that caliber weapon, because he
might not lose consciousness the first time. Lindholm also said that,
when shooting with two hands, turning the weapon upside down, it was possible
to shoot oneself that way.
Stuart James, a blood
spatter pattern expert from
James had done an
experiment to support his analysis. He withdrew his own blood, put it
into his mouth, and coughed against the same type of material from which the
suspect's pants were made. The droplets he produced were similar in size
and shape to those found on the pants. When questioned, he said that the
velocity of his cough would have been similar to that of Robert Perry.
In further support of
suicide, Craig claimed that he had no motive to kill his uncle. The
man had no money, and Craig loved him like a father. In fact, after his
own father had died, his uncle had raised him. Medical records indicated
that Robert's illness had grown worse, and his home nurse reported that he had
rejected traditional cancer treatment. Two days before he died, he had coughed
up blood and gone to the hospital, where doctors were unable to do anything for
him.
Hours before Robert died,
Carol Flynn called the hospital to report that he was having trouble
breathing. That same day, she had called 911 to say he had shot
himself.
Another witness said that
Robert was predominantly left-handed, but had used his right hand to
shoot. A neighbor and a hunting companion agreed that he was
ambidextrous. Both of these witnesses had heard Robert speak about
committing suicide.
Numerous character
witnesses testified that Craig was a peaceful man who had loved his uncle and
would not have shot anyone. He paid for all his uncle's expenses and took
care of his needs, from feeding him to getting him into bed. There was no
evidence that he considered his charge a burden. A nurse said that Craig
had remained positive that Robert might survive, despite the poor prognosis.
In support of the
homicide theory, there was testimony that, while Robert had grown worse, he was
taking simple medicines and resisting making discussions about his will.
He got angry with his nurse and told her, "You already have me in
the grave," an indication that he was fierce about living. Police
found a newspaper article about assisted suicide in a suitcase, along with
power of attorney documents.
Also, when police had
asked Craig Perry to leave the trailer on the day of the incident so they could
investigate, he yelled, "You think I killed him, don't you!"
Then after being confronted with the blood analysis evidence, Craig changed his
statement about hearing two pops to hearing one and then running to the
bedroom—presumably to imply that he arrived in time for the second shot.
A witness also testified
that when she found the second cartridge under the playing cards, Craig threw
it away, saying the police must not need it.
Clearly, the crime scene
was poorly processed. Overlooking a cartridge near the body and declining
to do any gun shot residue analysis, which may have resolved many questions,
cloud the issue.
On June 25, 2004, after
two days of deliberations, the jury announced its decision: Craig Perry was
acquitted of killing his uncle. Even the blood spatter evidence was
ambiguous enough to allow for reasonable doubt.
Bibliography
Chamberlain, Lindy.
Through My Eyes,
Evans, Colin. The
Casebook of Forensic Detection.
Geberth,
Innes, Brian. Bodies
of Evidence.
Lee, Henry C and Howard
A. Harris. Physical Evidence in Forensic Science.
MacDonell, Herbert
L. Bloodstain Patterns.
Nickell, Joe & John
Fischer. Crime Science: Methods of Forensic Detection.
Owen, David. Hidden
Evidence: Forty True Crimes and How Forensic Science Helped Solve Them.
Saferstein,
Richard. Criminalistics: An Introduction to Forensic Science.
5th Edition.
Schiller, Lawrence.
American Tragedy: The Uncensored Story of What Happened Behind Closed
Doors.
"The House that
Roared," Forensic Files, Court TV, January 11, 2001.
Young, Norman H. Innocence Regained, The Federation Press,
1989.