O.C. Eager to Add Power of DNA Lab to Crime Fight

In a bustling corner of the FBI headquarters, Special Agent Jack Quill is poring over an X-ray that bears an odd-looking pattern not unlike the bar code on a box of cereal.

But these horizontal lines have nothing to do with supermarkets. What Quill is holding on the oblong transparency is a piece of evidence that most likely will put a rape suspect behind bars.

The case is one of the 400 in which the FBI’s DNA Analysis Unit has completed its work since its opening last December. Work on 600 others, referred from law enforcement agencies throughout the country, is in progress.

“It takes us probably two to three weeks before we can even start a case now, because of our backlog,” said John W. Hicks, the FBI assistant director who runs the bureau’s sprawling laboratory division. “And it will probably get worse.”

That is one of the reasons that Hicks and other DNA experts, both in government and out, are applauding decisions by officials in Orange County and other jurisdictions to build their own laboratories to track down violent criminals through DNA “fingerprints.”

“We think it’s a very powerful technology that’s going to have a tremendous impact on law enforcement,” especially in identifying rapists and, to a lesser extent, murderers, Hicks said.

DNA testing technology represents a major breakthrough for law enforcement because it is a highly reliable method of positively matching blood, semen, hair or tissue samples taken from a crime scene with a blood sample taken from a suspect.

The older technology of blood serology is effective in excluding suspects, but it hardly ever produces a positive identification.

DNA, short for deoxyribonucleic acid, is an organic material found in the chromosomes of every human being. It carries the basic genetic code that determines individual characteristics.

By matching the repeating chemical patterns in those sections of DNA that bind genes together, scientists can routinely make identifications with certainties of one in several billion.

Eventually, law enforcement officials hope to build a computerized central DNA “fingerprint” identification system that will allow authorities to determine whether a series of rapes or murders across the country was the work of a single person, or whether a suspect arrested in one state was connected to violent crimes in another.

Despite questions raised by defense attorneys and civil libertarians, the technology has been accepted in trial courts in 34 states, according to an official of one of the two major private DNA testing laboratories in the nation.

Appellate courts in three of those states--Maryland, Virginia and Florida--have upheld the use of DNA testing, said John W. Huss, vice president of Cellmark Diagnostics in Germantown, Md., about 25 miles northwest of Washington. No appellate court has yet rejected the technology.

However, only two states and one local jurisdiction--Virginia, North Carolina and Nassau County, N.Y.--have opened DNA testing units in their own crime laboratories, according to the FBI. Six other state and local agencies, including the Orange County Sheriff-Coroner’s Department, are on their way.

The Orange County Board of Supervisors voted Oct. 17 to spend $200,000 to create a DNA unit in the county crime laboratory, $80,000 of which will be from private sources that have contributed to the Sheriff’s Advisory Council.

The decision was prompted in part by the disclosure that a suspect in the recent rape of a 12-year-old girl in Huntington Beach had been acquitted of a rape charge five months earlier because prosecutors were late in obtaining DNA evidence from a private laboratory. Had the evidence been received sooner, authorities have said, the man would probably have been convicted.

“The sooner we get it on-line, we feel, the better off we’re going to be,” said Lt. Richard J. Olson, a spokesman for the Orange County Sheriff’s Department. “We feel that evidence of this type is so overwhelming that in a lot of cases, rather than go to trial, we’ll get more guilty pleas.” And that, Olson said, would save both time and money.

Further, in the cases that go to trial, police officials said, an in-house DNA lab would eliminate the need to hire expert witnesses from private laboratories, which charge fees of as much as $1,000 for a single court appearance.

Exonerations can result in savings too, police said. If a DNA test determines early on that a prime suspect could not possibly have been the assailant, police are not wasting time or money going after the wrong person.

However, it is difficult to determine the cost-effectiveness of establishing a DNA unit in a public crime lab, Huss said. The FBI performs its analyses for local police agencies at no cost, but the growing demand may mean longer waits for evidence.

“I would say a laboratory that is going to do 10 cases a year, it would be absurd,” Huss aid. “But maybe it makes sense if you’re going to do 30 to 50 cases a year. . . . It’s very hard to calculate break-even, in a non-revenue environment and a non-competitive environment. But I think there are practical reasons to do it, chiefly chain of custody.”

The technology was developed in the early 1980s, and it has been refined in recent years. Its first widespread commercial application was in paternity testing. Huss estimated that 85% of his company’s business involves paternity cases, but its criminal work is significant.

Cellmark, for example, performed the lab work that led to the conviction last month of a 35-year-old woman for the robbery and murder of a worker at a Ventura hamburger stand. It was the first California case in which genetic testing evidence was introduced.

“We don’t view the entry of the public sector laboratories as a surprise or a problem,” Huss said. “When the FBI entered this business, our business shot up substantially because it gave the broadest possible endorsement to the technology.”

In addition to operating its own DNA lab, the FBI also trains law enforcement agents from all over the country in the use of the technology. The bureau expects that 120 people will take its DNA courses at Quantico, Va., next year.

Still, despite its promise, DNA identification does have limitations.

It is most effective in rape cases, because semen contains a large amount of DNA. In other cases, though, the blood samples or hair fibers sometimes prove to be too minute or too old to be effectively tested.

And it is not cheap. The FBI estimates that each test it performs costs about $100; Huss put the figure closer to $200 a sample.

Further, it is a painstaking procedure than may take as long as 12 weeks to perform, even without a backlog.

And at the moment, it can only determine whether a known suspect is connected with a particular crime. As yet, there is no DNA database comparable to the massive FBI fingerprint index that permits identification of an otherwise unidentified person.

Finally, DNA testing is subject to human error; one court so far has excluded DNA evidence because of a foul-up at the laboratory.

The testing process begins when a bloody piece of clothing or other article from a crime scene arrives at the lab. First, blood or semen samples are tested using traditional technology. If those tests do not eliminate a suspect, the samples are passed along to the DNA unit.

In an exacting process, the laboratory technicians extract pure DNA from the blood, semen or tissue sample, then purify it. The meter-long molecules of the double-stranded DNA are then cut into smaller pieces using agents known as restriction enzymes.

“Just think of them as biological scissors,” the FBI’s Quill said.

The DNA fragments are then placed on a sheet of gelatin that looks much like clear Jell-O. An electric current is applied, and the negatively charged DNA fragments migrate across the gelatin toward the positive charge, spreading according to their molecular weight.

The double strands of DNA are chemically split in half, then transferred to a nylon membrane through a process known as Southern Blotting.

The single DNA strands contain unique repeating patterns of organic chemicals that identify the individual who produced them (the matching strand contains complementary chemicals that fit the pattern precisely).

Once the DNA molecules are fixed on the membrane, the technician introduces a radioactive probe. A probe is a single strand of DNA with a known pattern of chemicals. The probes attach themselves to the single strands of DNA molecules at precise intervals, according to how often the pattern of chemicals is repeated. That pattern of repetition is unique to each individual.

When exposed to X-ray film, the radioactive probes create bands similar to the bar codes on supermarket items. Examiners such as Quill then read those bands, often using sophisticated computer equipment to assist in the analysis.

If the same probe creates the same band pattern on DNA strands taken from two different samples, then the examiner concludes that the two samples are from the same individual.

“There are about 90,000 rape cases that occur every year. . . , and only about half of those are solved,” said the FBI’s Hicks. “Many of these are probably the result of the mobile type of offender, selecting their victims at random and then moving on--the Ted Bundy type.

“That’s the type of person that this technology is going to be able to help us catch.”

DNA Fingerprinting This is the process a blood sample goes through to produce a DNA “fingerprint”, or indentification, of a person 1 Blood sample. 2 DNA is extracted from blood cells. 3 DNA is cut into fragments by a restriction enzyme. 4 The DNA fragments are separated into bands during electrophoresis in an agarose gel. 5 The DNA band pattern in the gel is transferred to a nylon membrane by a process known as Southern Blotting. 6 The radioactrive DNA probe is prepared. 7 The DNA probe binds to specific DNA sequences on the membrane. 8 Excess DNA probe is washed off. 9 At this stage the radioactive probe is bound to the DNA pattern on the membrane. 10 X-ray film is placed next to the membrane to detect the radioactive pattern. 11 The X-ray film is developed to make visible the pattern of bands that is known as a DNA fingerprint. Source: Cellmark Diagnosctics