Does California’s celebrated Laci Peterson case come down to a strand of hair? If so, Scott Peterson’s defense is trying hard to discredit it. A defense expert testified yesterday in a preliminary hearing that the strand was susceptible to contamination by police officers and lab technicians, the San Jose Mercury News says. “Contamination screws up results,” biologist William Shields of Syracuse University said during the hearing’s fifth day.
Prosecutors say the hair found wound around a pair of pliers at the bottom of Peterson’s fishing boat belonged to his wife, Laci, who was eight months pregnant when she disappeared Christmas Eve. They believe the hair helps prove Peterson killed her, took her body in the boat and threw her in San Francisco Bay, where she and her unborn son washed up separately in April.
The defense expert witness said the study of “mitochondrial DNA” used to identify the hair is unreliable, implying the hair might not belong to Laci. Defense lawyers want to convince Judge Al Girolami in Modesto, Ca., to prohibit the hair from being admitted into evidence.
Peterson, a 31-year-old fertilizer salesman, was having an affair with Fresno massage therapist Amber Frey when his wife disappeared. Frey is expected to testify later this week.