A dog handler testified Wednesday that her animals picked up Laci Peterson's scent along the rim of her husband's boat and at the marina where Scott Peterson (search) says he went fishing the day his wife disappeared.

The testimony was part of a hearing to determine what evidence would be admitted at Peterson's murder trial.

Prosecutors maintain the dogs provide important clues to how Peterson allegedly disposed of his pregnant wife's body, while the defense argues the canines are unreliable.

Peterson, 31, could get the death penalty if convicted. Jury selection is set to begin next Thursday, and the trial could last five months.

Eloise Anderson, who trained a Labrador retriever (search) that sniffed Peterson's boat and warehouse for signs of his wife, said the dog tracked her scent at the Berkeley Marina (search). Peterson said he launched his boat from the marina for a fishing trip on Dec. 24, 2002 -- the day his wife vanished.

Anderson said the dog then followed the scent to a pylon at the end of a pier where a boat could be moored.

A second dog that specializes in finding cadavers also picked up traces of Laci Peterson's scent, this time along the boat's rim, Anderson said. Laci Peterson's family has said that she was unaware her husband had purchased a boat.

That dog also picked up the woman's scent on a tarp stored in a shed in the Petersons' backyard. Prosecutors allege Peterson wrapped his wife's body in a tarp, a contention dismissed by the defense.

Defense lawyers seized on Anderson's testimony that a strong odor of fertilizer made a definitive scent impossible to establish. Peterson worked as a fertilizer salesman before his arrest.

Throughout the day, defense lawyers picked apart Anderson's testimony, saying there were too many opportunities for the dogs to make mistakes -- as they had many times during their training.