Quadra linked to DNA at rape scene

The prosecution's final two witnesses to testify in a rape and kidnapping trial provided compelling evidence Monday, scientifically linking the defendant to DNA and a modified set of handcuffs recovered from the crime scene.

Aristotle Quadra, 31, is on trial for attempted murder, rape, kidnapping with intent to rape and six other felony charges in connection with a Feb. 7 attack on a woman and her 20-month-old child that started in the Bennett Valley Safeway parking lot.

Quadra's attorney may present defense witnesses Thursday and the jury could begin deliberating Quadra's fate early next week.

The woman testified that Quadra pushed her into her SUV as she was strapping her son into his car seat and threatened the boy's life unless she did as he ordered. She said he then forced her to drive to a secluded parking lot a few miles away, where he handcuffed her, raped her and stabbed her about 14 times with an ice pick.

She was able to break free and stomp on the car horn, causing her attacker to flee. He was arrested three days later after a former co-worker identified him from a composite sketch based on the woman's description.

On Monday, a criminalist from the state Department of Justice crime lab testified that DNA recovered in a sexual assault examination of the woman matched a sample of blood taken from Quadra after his arrest.

The probability that the sample DNA, a person's genetic fingerprint, could have been from someone other than Quadra is statistically astronomical -- between one in 1.6 sextillion and one in 4.6 sextillion, depending on the person's ethnicity. A sextillion is a one with 21 zeroes behind it.

Criminalist Sarah Calvin said she calculated the probability using FBI population databases that show how often certain genetic markers are found in specific locations in a person's genetic structure.

Quadra's attorney, Barry Collins, objected to the testimony because the FBI databases use only the three major ethic groups, Caucasian, African-American and Hispanic. Quadra, he said, is Filipino.

Another criminalist, Richard Waller, testified that two broken metal pieces found jammed in the handcuff locks matched another broken piece of metal found at the end of a rope police found in Quadra's apartment.

Using images taken from a microscope, Waller described to the jury how he examined the "hills and valleys" and "nooks and crannies" of the ends of the metal nubs to determine if they may once have been connected.

The highly magnified ends, which looked similar to lunar landscapes, would show corresponding contours if they had been part of the same piece of metal at one point, he said.

"They would fit together like a lock and key," he said.

After showing several photos comparing the pieces, he concluded they were a match: "These two items were once a single unit."

He also testified that a long, thin silver chain that connected the two handcuffs appeared to match an identical-looking length of chain found in his apartment.

Prosecutor Tashawn Sanders said she likely will rest her case on Thursday after more than 120 pieces of evidence are entered into the court record.

Collins reserved his opening statement until after the prosecution's case is finished. He has asked only a few questions in cross-examination of the prosecution's 31 witnesses.

He has challenged the allegation of premeditation in the attempted murder charge and whether the victim's wounds constitute "great bodily injury." A doctor testified last week that they required no medical intervention aside from antibiotics.

Collins has also suggested that Quadra's behavior may have been influenced by his use of methamphetamine the day of the assault.

Quadra faces a life prison term if convicted of the most serious charges. He is in custody without bail at Sonoma County Jail.

Contact Staff Writer L.A. Carter at 568-5312 or lori.carter@pressdemocrat.com.