The JonBenet Ramsey Case

Forensic Evidence

Much detective work in JonBenet Ramsey murder case conducted under lab microscope

By Joseph B. Verrengia

By Joseph B. Verrengia
Rocky Mountain News Science Writer


No witnesses, no bloody glove, no confession.
Only a little girl's body covered by a blanket in the basement of her family's mansion and a handwritten ransom note found upstairs.
To solve the slaying of JonBenet Ramsey, Boulder police must rely to a great extent on the results of forensic tests being conducted in crime laboratories.
The question is whether there is a sufficient amount of physical evidence -- including body fluids, fingerprints, hair, fibers and handwriting -- to conclusively determine who sexually assaulted and strangled the 6-year-old beauty queen and youngest child of John and Patsy Ramsey.
And the looming problem for police and prosecutors, according to forensics experts, is whether the evidence is in good condition. Or whether lax procedures -- including John Ramsey's search of the house eight hours after police were called, his discovery of his slain daughter and his handling of the body as he carried it upstairs -- resulted in key evidence being hopelessly contaminated.
"Many crimes, especially major ones, are solved in the laboratory,'' said Nelson K. Jennette, a Montrose forensics investigator who specializes in hair and fiber.
"His moving the body certainly didn't help anything,'' Jennette said. "It's certainly in the realm of possibilty that he contaminated the scene.''
The JonBenet case, he said, is fascinating from a forensics perspective because so many basic questions remain unanswered and so many possibilities still exist about what happened in the Ramsey house Christmas night.
Given the career-damaging cross-examinations that forensic investigators endured in the O.J. Simpson criminal and civil trials, Jennette said scientists who undertake laboratory tests on the evidence in the Ramsey case must take extra care to "report just what you find.''
Boulder Police have disclosed little during its five-week investigation into the Ramsey murder, and the Colorado Bureau of Investigation won't discuss results of its tests of forensic evidence.
JonBenet died by asphyxiation caused by strangulation, according to the Boulder County coroner. The Rocky Mountain News disclosed that her skull was fracutured, she was sexually assaulted and that blood and possibly semen were found at the scene.
No one has been publicly named or eliminated as a suspect.
JonBenet's parents and siblings have provided police with blood, hair and handwriting samples for comparison. So have some family friends and employees, as well as some employees at Ramsey's firm, Access Graphics Inc. in Boulder.
Genetic fingerprinting and other tests probably won't be completed until early this month.
Boulder police spent 10 days collecting physical evidence at the Ramsey's sprawling home near Chautauqua Park. Investigators removed doors, carpet sections and other large items, as well as suitcases believed to contain clothing, bedding and other personal effects. They photographed a maze of footprints in the snowy yard.
That suggests a very thorough collection process, forensics experts said.
It also means there is a lot of evidence to sift through, much of it under microscopes. Generally speaking, more specimens are better than a few. But that's not necessarily true if evidence has been disturbed or comingled, or if it hasn't been meticulously handled and catalogued.
Sorting through it all and completing dozens of sophisticated tests, from genetic fingerprinting to dissolving fibers in acid to determine their contents and origins, could take weeks or months.
"You have no control over the evidence deposited, the state it's in or how much is there,'' said geneticist Moses Schanfield, director of Analytical Genetic Testing Center in Denver. "It's about trying to work with what you have.''
Then there is the matter of what the results mean to the case. With the exception of fingerprints, forensics evidence rarely is conclusive.
A forensics match -- even with DNA -- doesn't prove a person committed a crime; additional evidence almost always is needed for a conviction.
Forensics testing is much better at demonstrating who didn't do it and who wasn't there.
"The purpose of all forensic evidence is exclusionary,'' Schanfield said. "Then the question is whether the evidence is individualizing.''
Investigators are using genetic testing to sort through potential
suspects in the JonBenet case and try to zero in on the killer.
DNA is likely being extracted and analyzed on crime scene samples of hair, blood and possibly semen. They would be compared to genetic material in blood and hair samples provided by family and friends.
After years of debate over family variabilities, genetic patterns of ethnic groups and reliability of the technology, lawyers and scientists now agree that DNA testing can match the blood, semen or tissue recovered at a crime scene to a given individual.
Assuming, of course, that technicians properly collected the samples and the testing procedures were correctly followed.
Still, geneticists don't declare that the DNA in a crime scene sample and the genetic material provided by a suspect absolutely are one and the same.
Rather, they describe it as a random-match probability. That is an estimate of the chance that a randomly selected person will share the DNA pattern present in both the defendant and the crime scene sample.
In most cases, the random-match probability is one in a million, one in a billion or higher that a crime scene sample originated from someone other than the suspect whose DNA matched.
Geneticists do not match a person's entire genetic code to the code contained in a crime scene sample. That's because scientists have not yet mapped the entire human genome. And even if they had, crime labs would not have the computing power to run such complete tests.
The nucleus of every cell contains a copy of DNA, or deoxyribonucleic acid. It's a thin, coiled ribbon consisting of two twisted strands, each of which contains 3 billion repeating chemical units called nucleotides.
Each nucleotide contains four different chemicals, called bases, in a myriad of sequences.
Only about 2% of DNA is genes; the rest is called "junk DNA,'' and its biological purpose is unknown. But given all the biochemical combinations, the chances of two people having exactly the same genetic pattern are incredibly slim.
Forensic experts compare markers, or representative samples of DNA where it would be extremely unlikely for two people to have the same genetic pattern in those locations. They typically check the DNA pattern in four to six places to determine individuality.
"We never can make absolute statements -- that is, to the exclusion of everyone else,'' Schanfield said. "If we're typing a limited number of markers, at some point one can say it is an individual with a reasonable degree of scientific certainty. But that's a different level of statement than what, say, a fingerprint examiner would say.''
Schanfield's caution reflects the tests' statistical ambiguities, but the accuracy of a DNA identification rarely is directly challenged anymore.
Instead, defense attorneys more frequently contend that lab results are skewed by the crime scene sample being mishandled, degraded or contaminated to the point where test results are not trustworthy.
Forensic experts said the Ramsey case presents some special circumstances that undoubtedly will complicate the interpretation of test results, and possibly their usefulness in court.
» Biological evidence: Police have collected blood and a small amount of fluid that could be semen from the crime scene. The condition of the sample would be crucial, even more than the volume of fluid collected.
"The smaller and faster a sample dries, the less damage there is to the DNA and the better chance of getting a good (genetic) profile,'' Schanfield said.
"If there is a pool of blood and it takes forever to dry before it is sampled, you are less likely to get DNA from that sample.''
DNA in blood, semen or other fluids is very unstable when it is wet. That's because it is fragile, and body fluids frequently contain enzymes that can destroy DNA.
There is no specific time limit on DNA's viability. Nor is there a specific amount that must be obtained for an accurate genetic test.
A testing method employing a process called the polymerase chain reaction, or PCR, can handle a sample of 50 cells -- an amount that may not even be readily visible. PCR acts as a genetic copying machine to create duplicates of the material. The magnified sample is easier to handle in tests.
A method known as RFLP checks more locations on the genetic pattern but takes weeks to complete and requires a much larger sample.

But PRC testing will destroy the small amount that investigators have. The law requires that a defendant's lawyers also be able to test some of it or monitor the state's tests. And although there is not yet a defendant in the case to notify, tests on the fluid have been delayed due to police concerns over this issue.
» The home: Skin, hair, clothing fibers and other microscopic traces of JonBenet are likely to be everywhere in the house, as well as traces of every family member and perhaps frequent visitors.
If no clear physical evidence of an intruder is present, and police suspicions narrow to the people closest to the girl, it could be difficult to determine what traces are crime-related and what are not.
» The basement: It's one of the worst places for investigators to find a body because the basement isn't as clean as upstairs rooms. If investigators used powerful vacuum sweepers to collect everything that might have been overlooked, the process could jumble crime scene dirt with older, unimportant debris layers.
"We're interested in what was deposited last,'' Jennette said. "In a basement, you're dealing with cobwebs and dirt and fibers in layers that were deposited years ago. That complicates things.''
» John Ramsey's actions: Discovering his daughter's body, removing the duct tape from her mouth and carrying the body upstairs has been described as the natural reaction of a grief-stricken father. But from a forensics perspective, it was a major blunder.
Fibers, hair and debris left by the killer might have been dislodged in the process -- possibly from the girl's body, forensic experts said. Unless Ramsey was "wearing an astronaut suit'' that neither sheds or attracts, Jennette and others believe his actions probably resulted in some materials being transferred between him and the victim.
"When a crime is committed, the person leaves something behind and takes something away,'' Jennette said. "It can be microscopic in size. That (moving the body) can contaminate things big time.''

February 2, 1997