O.C. DNA Testing Laboratory Is Nearing Test of Its Own in Court


When jurors acquitted Kyle Joseph Borges of rape in 1989, prosecutors attributed their defeat to their inability to get crucial DNA evidence into the case.

Earlier this month, another rape case against Borges came to an end. But this time, prosecutors had the evidence--DNA evidence--tying him to the crime. In this case, unlike the earlier one, Borges saw the handwriting on the wall and entered a guilty plea before the trial began, according to law enforcement authorities.

"(Borges’) guilty plea underscores . . . the fact that the guilty party knows that we have the evidence and there’s no way to get around it in the court,” Orange County Sheriff Brad Gates said.

It was the Borges case--and the public uproar and political controversy that followed his arrest in the rape of a 12-year-old girl just five months after his first acquittal--that led to creation of the Sheriff’s Department’s DNA testing laboratory, the first of its kind west of the Mississippi.

Since the lab was created 10 months ago its scientists and technicians have been quietly gathering more than 1,000 individual samples of DNA from different ethnic groups to use as a comparative data base. The samples, which come from Caucasians, blacks, Latinos and four subgroups of Asians, are derived from blood given by the Red Cross.


Technicians first analyze DNA found at a crime scene, then compare the suspect’s DNA. If there is a match, the technicians determine what the chances are that the match would occur by using statistics drawn from the database.

“We always said that DNA is very powerful (as a law enforcement tool). We have been focusing on cases where we know that we have a good chance of success in court,” said Margaret Kuo, chief criminalist at the lab.

“We can narrow down suspects to one in a million or even one in a billion,” she said. “That’s why it’s so powerful.”

DNA technicians have also completed work on 18 criminal cases that include sexual assault, murder and statutory rape involving pregnancy.

Most recently, the San Clemente Police Department has handed over evidence taken from three of five women who police theorize were raped by one man. The evidence will either prove the police belief that a serial rapist is loose in that South County beach city or that the women were raped by different men, Kuo said.

The analysis will take about six weeks to complete.

Although 12 cases involving DNA are now pending in Orange County courts, none of the evidence was produced by the county lab, said Deputy Dist. Atty. Dennis Dean Bauer, who specializes in DNA cases. Ten of the cases involve sexual assault, and two are murder cases.

Tests that led to Borges’ plea were completed by a federal laboratory before the Orange County facility opened. Others were prepared by private DNA laboratories and took up to six months to complete.

The Sheriff’s Department lab is nearing a critical test of its own: In less than a month, its procedures will be debated in court and a judge will decide whether the new, sophisticated, powerful--and still controversial--tool for criminal detection, as practiced in the Orange County lab, will be accepted as evidence.

The case of David R. Ricklef, accused of raping women in Garden Grove, Anaheim and Fullerton at knifepoint, will be the first in which the lab’s work will be scrutinized in court.

“I have tremendous confidence in the staff and laboratory, and they’ll be prepared,” said Sheriff Gates, who spearheaded creation of the laboratory last May.

The lab has concentrated on building an extensive database, which even critics say is among the best in the country.

“The Orange County laboratory has taken some major steps,” said William C. Thompson, a UCI criminal justice professor who is also a paid defense witness against the use of DNA evidence in trials. Calling the laboratory “third generation,” Thompson said the Orange County facility has gone beyond its predecessors.

“I commend them for taking a serious approach to controversial issues,” he said. “I think that’s impressive and promising.”

The 6-year-old and often controversial DNA “fingerprinting” technique, which matches a suspect’s unique genetic makeup to biological evidence such as blood, semen or hair left at a crime scene, has been gaining popularity among prosecutors nationwide.

Although it has not been accepted in all states, several hundred convictions around the country have been based on DNA evidence, authorities say. In California, two cases are now before appellate courts.

But despite the high confidence level among criminal justice officials, there are still doubts about the complicated process, which was devised in 1985.

“It’s clear that DNA results are not always infallible,” Thompson said. “Some have argued (that) sometimes there is an element of ambiguity. I don’t think a match on a DNA print is (conclusive) beyond a shadow of a doubt.”

“I don’t think anybody can characterize the disagreement in the scientific community as trivial,” said Laurence Mueller, a UCI population geneticist who has also testified around the country about problems inherent in the testing procedures.

“The issue is not going to go away,” Mueller said.

Critics say, however, that the process often can be skewed, either through DNA contamination or laboratory error. They also say there are questions about the validity of the statistics.

Of the four Orange County cases involving DNA that have reached local judges, the DNA evidence was rejected in only one of them, according to Deputy Dist. Atty. Bauer. New charges have been filed against that defendant, Danny Harris, accused of serial rape, and Bauer said he expects to prevail at a hearing scheduled for next month.

Nonetheless, Bauer said he welcomes the DNA criticism because it has helped to revise and shape the testing procedures adopted by the Orange County lab.


This is a process a blood sample goes through to produce a DNA “fingerprint,” or identification, 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 radioactive 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.