Silent testimony from cells Md. lab gains fame analyzing DNA in O. J., Ramsey cases


GERMANTOWN -- The deliveries that arrive at this quiet, nondescript suite, tucked away in a shoe box of an office building just off Interstate 270, are anything but nondescript: A hair. A bloodstained swatch of fabric. A lipstick-smudged cigarette butt. A torn fingernail. An ax.

They are all remnants of sordid episodes of murder, rape, acts of betrayal.

Each item will be combed for a trace of human life, a genetic calling card that can be used to help answer such questions as: "Who killed JonBenet Ramsey?"

Cellmark Diagnostics is the nation's largest private forensic laboratory for testing of DNA (deoxyribonucleic acid), the material that contains an organism's genetic code and transmits the hereditary pattern.

The lab first achieved international celebrity when it performed tests on blood samples for the O. J. Simpson murder trial and its lab director testified in court.

The company's fortunes have soared in the past couple of years, with its workload growing 20 percent each year, its staff expanding, plans in the works for a move to grander digs this year -- and more sensational, high-profile murder cases landing at its heavily secured front door in this Montgomery County suburb.

Most recently, the Maryland lab, which specializes in criminal investigations but also performs DNA testing to determine paternity, has been examining evidence connected to the slaying of JonBenet Ramsey, the 6-year-old pageant winner in Boulder, Colo.

Its work is expected to be finished possibly as soon as this week.

In the past decade, the field of DNA testing has exploded, with Cellmark -- which opened in 1987 with a sister operation in England -- among a field of 130 public and a dozen private crime labs in the country doing such analysis.

Considered the blue-chip private lab for DNA "fingerprinting" by those in the forensics industry, Cellmark tests samples of body fluids and other biological evidence for 500 to 600 cases a year, most of them murders or sexual assaults, from all over the Western Hemisphere.

"What we are doing is to establish identity beyond a reasonable doubt in the mind of a juror," says Cellmark's director of operations, Mark D. Stolorow.

"By examining four or five or six points on a person's DNA, we can reach a level of individuality which can answer the questions in the courtroom for whose blood matches the evidence at the crime scene and whose blood does not."

Unassuming site

At this modest suite of laboratories, there is little to suggest the intrigue, the violence, the life-or-death dramas that often hinge on the white, gelatinous blobs -- DNA -- that float in tiny test tubes.

The main lab is bright, quiet, still -- and dotted with signs that caution "Radioactive Materials" or "Biological Hazard, Wear Your Goggles."

Behind an unmarked, locked door is the evidence vault lined with refrigerators and freezers that contain the samples of blood and other biological materials that have been either hand-delivered or shipped to the lab.

Another room holds the larger pieces of evidence -- a sofa, a headboard, a car door, a piece of pavement -- that occasionally arrive, often with invisible stains of body fluids that scientists can detect with a laser.

Cellmark's scientists -- the company employs 15 molecular biologists among its staff of 35 -- have testified in about 400 trials (for a fee of $1,200 a day plus expenses), 90 percent of the time for the prosecution.

Role in conviction, appeal

Such testimony, for instance, played a key role in the 1995 murder conviction of Scotland E. Williams, who was sentenced to death in the slayings of two lawyers near Annapolis.

In an extraordinary combination of detective work and science, DNA was extracted from mouth cells lifted from a drinking glass left at the crime scene. It matched Williams' DNA, a Cellmark scientist told the court.

But that DNA testimony also led in part to the Maryland Court of Appeals' decision to grant Williams a new trial.

The state's highest court ruled in July that Williams' lawyers, who claimed such DNA testing techniques were susceptible to contamination, were not allowed sufficient opportunity to cross-examine the Cellmark scientists about the frequency of contamination at its lab.

A new trial is scheduled to begin Nov. 3.

Another high-profile case was a 1988 murder in which no body was found. Gregory Tu, a Potomac restaurateur, was convicted of first-degree murder in the disappearance of his common-law wife, Lisa Tu, after bloodstains on the basement floor yielded DNA determined to be hers.

The lab took blood samples from Lisa Tu's first husband, who was living in Hong Kong, and their teen-age son.

From their DNA patterns, scientists could determine what hers must look like. A Cellmark scientist testified in court that it was "extremely unlikely" that the blood in the basement came from anyone other than Lisa Tu.

Proof of innocence

On the flip side, Cellmark's work has exonerated some accused of crimes, often after they have been convicted and have served time in prison.

In a 1987 Indiana case, for instance, Dwayne Scruggs was convicted of rape and robbery, and sentenced to 40 years in prison. Five years after his conviction -- and after an appeal that upheld the guilty verdict -- Scruggs' public defender requested that DNA testing, not available at the time of the original trial, be performed on the biological evidence.

Analyzing DNA from a bloodstain from the crime scene as well as from seminal cells from a vaginal swab from the victim, Cellmark scientists excluded Scruggs as the source.

After serving more than seven years in prison, he was released, with all the charges against him dismissed.

The lab's forensic work gets most of the attention, but about half of Cellmark's DNA analyses -- about 2,000 tests a year -- are to determine paternity.

For the $595 testing fee, clients buy confidentiality as well as answers.

High-profile figures

"Unfortunately, I will have to take to my grave with me the long list of celebrity tests that we do in this laboratory," Stolorow says.

"But it would shock you if you had any concept of how many frequently observed names in the press come to us as alleged parents."

One such name was former Detroit Mayor Coleman A. Young, who withdrew a suit he filed in 1989 challenging a paternity claim made against him after Cellmark's tests concluded that the then 71-year-old politician was, in fact, the father of a 6-year-old child.

The lab has also served as the final arbiter in resolving other sensitive disputes.

Last year, a runner in the Summer Olympics was disqualified after her urine sample tested positive for drugs.

Insisting the sample was not hers and must have been swapped or misidentified, the athlete appealed the decision.

Her lawyer, in cooperation with the International Olympic Committee, sent Cellmark the urine specimen and a sample of the runner's blood.

The lab found the DNA in the two samples matched, and the disqualification stood.

Stolorow says the company gets all sorts of unusual requests.

Some it cannot oblige because there is no DNA present -- such as in the case of the woman who wanted to make sure the 10 pounds of ashes she was given were really those of her cremated mother.

Some it can: "There are wives who ask us to examine hairs that are found on the clothing of their husbands or examine cigarette butts from the car ashtray with lipstick on them," he says.

"There are all sorts of sordid human activities for which DNA testing is going to help them, in their mind, solve a domestic problem."

And there are less sordid activities as well.

The lab's DNA analysis is used by doctors to help monitor the acceptance of donor bone marrow in transplant patients.

And the lab was called upon by the U.S. military to help identify casualties from the Persian Gulf war through DNA analysis of small or badly incinerated body parts.

The lab has a one-year contract with the Defense Department to try to find ways to detect biological materials, and thus DNA, from bombs or other evidence in terrorist-related cases.

The growth of DNA testing in the past decade -- and Cellmark's success -- is largely due to the longevity, stability and accessibility of DNA.

Stolorow says the genetic marker, which is exactly the same only in identical twins, can be extracted from anything from a tooth to saliva cells on a ski mask, and can be culled from a sample smaller than the period at the end of this sentence.

In the Dr. Sam Sheppard murder case that inspired "The Fugitive" TV series and movie, DNA tests were performed this year on evidence that had been sitting in a Cleveland courthouse for 43 years.

The DNA analysis, performed by Dr. Mohammad Tahir at the Indianapolis and Marion County crime laboratory, is to be presented at a pre-trial hearing on June 2 and might clear the late doctor of the murder of his wife in 1954.

Technique becomes accepted

Courts, once leery of the revolutionary but still relatively new forensic tool, now admit DNA evidence in 98 percent of all trials in which it is introduced.

In the 11 percent of cases in which the admissibility of DNA evidence has not been upheld on appeal, judges have most often cited problems with the statistical claims made.

In fact, the statistical interpretation of DNA evidence remains controversial.

Lawyers agree that DNA evidence can conclusively exclude a suspect.

But because only DNA fragments are compared -- as opposed to an individual's entire genetic code, which would be comparable to a 3 billion-rung ladder -- defense lawyers often argue that a match is never 100 percent and that accuracy is exaggerated.

"There's a huge danger that juries tend to view DNA evidence as so conclusive it overrides everything else in a case," says public defense lawyer Ira Mickenberg.

"Unless the defense is allowed to challenge it, you're pre-empting any kind of a fair trial."

In the Simpson case -- in which the jury saw, for instance, a match between the blood found on a sock in O. J. Simpson's bedroom and the blood of Nicole Brown Simpson, as well as a match between the blood from the pavement outside Ms. Simpson's condo and her former husband's blood -- the defense challenged not the reliability of the DNA results, but the collection of the evidence, arguing that the blood evidence was contaminated and planted.

Stolorow says the trial served as a "wake-up call" for those who collect evidence.

Cellmark allows scientific experts for the opposing counsel to observe its work.

In the Ramsey case, the district attorney's office gave JonBenet's parents the opportunity to have their own experts witness the Maryland lab's work, but they declined.

James E. Starrs, a professor of law and forensic science at George Washington University, says that, although generally reliable, DNA evidence can still be problematic in terms of lab contamination and the integrity of old evidence.

He says Cellmark, the only nongovernment lab to be accredited by the American Society of Crime Laboratory Directors, has had fewer problems than other labs.

Limiting errors

Still, there have been errors. Cellmark made two mistakes on proficiency tests, one in 1988 and the other in 1989.

After those, Stolorow says, the lab instituted new quality assurance measures and has never been found in error in any of 400 tests administered since, giving the 10-year-old company an error rate of 0.286 percent.

"There are people who are going to be sent to death, who will have 2,000 volts of electricity sent through them as a result of the work we're doing in this laboratory," the Cellmark director says.

"It's just as important as making sure Apollo 13 doesn't run out of oxygen. The impact is irreversible.

"If you make a mistake, somebody dies."

Pub Date: 5/11/97

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