Week 17

May 15 - 19, 1995

Dr. Robin Cotton of Cellmark Diagnostics conceded that her laboratory in the past had twice made false matches in DNA testing due to sample handling error or cross-contamination, in which blood from one sample was inadvertently mixed with blood from another.

Testifying for a sixth day, Cotton also disclosed that some data used for comparisons in the Simpson case included tests on only two other blacks. Cotton explained that in calculating the rarity of Simpson's genetic profile, she relied on five genetic markers or "loci."

"And so in your data base, the number of people that you have typed like Mr. Simpson across all five loci is just two people, isn't that right?" defense attorney Peter Neufeld asked.

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"Across all five, yes," Cotton said.

Although the sample of only two blacks who were tested for all of the same genetic markers as Simpson was very small, Cotton said, "I don't think that's a critical feature."

Neufeld repeatedly questioned Cotton about Cellmark's procedures in an effort to raise doubts about the test results.

Cotton acknowledged that two errors were caught in 1988 and 1989. She noted the errors happened during quality-control tests -- not actual DNA cases -- and said Cellmark has undergone more than 100 quality-control tests without mishaps since then.

Neufeld suggested the lack of oversight for procedures at Cellmark cast doubt on the trustworthiness of its results, but Cotton held firm.

"Would you agree ... that you really have no scientific basis for estimating your laboratory's error rate?" Neufeld pressed.

"No, I don't agree with that," Cotton said.

At one point during the testimony, Judge Lance Ito lost his temper with Neufeld and Cotton, telling the lawyer and witness to stop arguing with one another and talking at the same time.

MAY 16 - The prosecution introduced scientific evidence linking O.J. Simpson to the murder of Ronald Goldman.

The state's second DNA witness told jurors that the blood taken from the glove found on Simpson's estate matched Goldman's blood. This was the first time jurors heard about the alleged blood match since opening statements.

The witness, Gary Sims, a senior criminalist with the California Department of Justice's DNA laboratory, also testified that DNA tests showed blood on the socks found in Simpson's bedroom matched Nicole Brown Simpson's blood. About 20 stains were found on each sock. Sims is expected to testify Wednesday about the frequencies concerning blood from the socks and from the glove. He is also expected to testify about blood stains found in Simpson's Ford Bronco.

Like the previous witness, Dr. Robin Cotton of Cellmark Diagnostics, Sims testified about RFLP testing. But the RFLP tests done at the California lab were different from the tests conducted at Cellmark. The prosecution hopes having blood matches from two different labs, which conducted two different tests, will strengthen the impact of the genetic evidence.

Sims, a criminalist for 19 years, joined the Department of Justice in 1990. He helped establish the department's DNA lab and has previously testified eight times about DNA results.

Lawyers spent part of the day arguing -- outside the presence of the jury -- about the prosecution's desire to elicit testimony from Sims that the defense had ample opportunity to conduct DNA tests on the blood samples. Over defense objections, Judge Lance Ito allowed Prosecutor Rockne Harmon to ask Sims several questions on the subject. Sims said the lab tested 108 samples in the case, including substrate controls. Of those, Sims said only a few samples were totally consumed. As a result, the prosecution argues the defense could have tested the rest of the samples. The state wants the jury to wonder -- if the defense has problems with the DNA results -- where are the defense's own results?

MAY 17 - The prosecution tried to pull together its "trail of blood" theory by presenting evidence found in the Ford Bronco, O.J. Simpson's bedroom and from the crime scene.

The most significant evidence presented by scientist Gary Sims was that blood consistent with Simpson's and the two victims was found inside the Bronco.

Three stains lifted from the center console of the vehicle appeared to be mixtures of blood containing the genetic patterns of Simpson, Nicole Brown Simpson and Ronald Goldman, Sims said. Another stain on the center console had the genetic material of Simpson and Goldman and a stain on the driver-side carpet showed Nicole Simpson's genetic pattern. Two other other stains only had Simpson's genetic signature, Sims added.

The testimony was the first time anyone has suggested that Goldman's blood was in the Ford Bronco, which the state believes Simpson drove on the night of the murders.

Sims, a top scientist from the California Department of Justice's DNA laboratory, was testifying for a second day. He did not offer any statistics showing how many other people had the same genetic patterns as those found in the blood stains.

Concerning the glove found on Simpson's property, Sims testified about ten bloodstains, including a stain inside the glove that matched Goldman's blood. According to Sims, the blood of Simpson and the two victims was all over the glove, with most stains being a mixture.

Sims also offered important testimony about the location of the blood found on the socks. Sims testified that blood consistent with Nicole Simpson's was found near the ankle area. The prosecution believes that if someone is wearing pants and shoes and walking through blood, the splatter would hit the area of the sock that is exposed -- the ankle. In addition, blood consistent with Simpson's was found in the toe area. The prosecution believes the blood got there when Simpson took off the sock with his cut, bleeding finger.

MAY 18 - The genetic-match statistics in the O.J. Simpson trial soared to unbelievable levels based on the combined test results from two laboratories that conducted DNA tests on bloodstains from the crime scenes.

Gary Sims, a criminalist with the state Department of Justice, used DNA test results from both his lab and Cellmark Diagnostics to increase the odds that Simpson's blood was left at the crime scene, and that Nicole Brown Simpson's blood was on a sock found in Simpson's house.

Sims put the combined-test odds that it was someone's other than Simpson's blood found near the bodies of Nicole Simpson and Ronald Goldman at 1out of 240,000. That is an increase from the previously expressed odds of 1 out of 5,200 on the basis of testing done at Cellmark Diagnostics.

The numbers show how many people have a certain type of DNA pattern, and are used to help narrow the possibility that a particular person's known genetic signature matches that of a collected stain.

The chances that it was someone other than Nicole Simpson's blood on the sock found at the foot of Simpson's bed soared to an astronomical level -- the combined calculations being 1 out of 21 billion, Sims said. By comparison, Cellmark put the calculation at 1 out of 9.7 billion.

MAY 19 - On what would have been Nicole Brown Simpson's 36th birthday, the prosecution described in gruesome detail its verson of how she was killed.

Assistant district attorney Brian Kelberg said that O.J. Simpson incapacitated his ex-wife with blows to the head and at least four stab wounds. As she lay facedown, he grabbed her by the hair with his left hand, put his foot on her back, pulled her head up and cut her throat left to right, severing the carotid artery, Kelberg said.

In arguing over the admissibility of 40 to 50 autopsy photos, Kelberg said the cut was so deep it partially severed her vertebrae, Kelberg said, in arguing over the admissibility of 40 to 50 autopsy photos.

The jury, which was not present for this description, needs to see the autopsy photos because they prove the killings were committed by someone in a rage, such as an abusive ex-husband, Kelberg argued.

Defense lawyers Robert Shapiro and Gerald Uelmen argued that the photos would "inflame the passions" of jurors and could cause them to render a verdict based on emotion rather than evidence. The defense said the photos do not add anything to the purpose of coroner testimony, which is to establish the time and cause of death.

Judge Lance Ito said he will rule Wednesday or Thursday on this matter. If he allows the photos, they will be placed on boards in front of the jury box. They will not be placed on the overhead projector, and they will not be allowed to be shown by the media.

In the morning, defense lawyer Barry Scheck continued his cross-examination of Gary Sims, a forensic chemist with the California Justice Department, by trying to show the blood evidence was contaminated, thus invalidating DNA results.

Sims agreed with Scheck that a minuscule amount of blood is needed to create a DNA sample. The DNA test known as RFLP can be done with as little as 50 nanograms of blood, and perhaps less. A drop of blood has about 1,000 nanograms.

Even smaller amounts of blood are necessary for PCR, another DNA test.

Establishing the extremely sensitive nature of such testing, Scheck argued that the sloppy work habits of the Los Angeles police, including the use of unclean gloves and unsanitized tools, contaminated the blood samples.

At the end of the session, Scheck tried to point out that blood could have been contaminated or planted without Sims knowing it.

"Do you know from your own personal knowledge how and when that blood got on the sock," Scheck asked, asserting the defense theory of a police conspiracy. Sims said no.

Before the jury were sent away for the weekend, they sent a note to Judge Ito requesting that court hours be increased to a full day Friday and a half day Saturday.

At the end of the day, prosecutor Rock Harmon told Judge Ito that a photo taken June 13, the day members of the defense team visited the crime scene, reveals a blood spot on the back gate that did not appear in a July 3 photo, suggesting that the defense may be concealing evidence, an assertion that Scheck denied.

Judge Ito ordered defense lawyer Carl Douglas to review defense records and report his findings Monday.

WEEK 18