Scott Peterson's (search) defense lawyer worked again Tuesday to shift the jury's attention to other potential suspects he claims could have killed Laci Peterson (search), but were not checked out fully.

Detective Ray Coyle already testified that Modesto police investigating Laci Peterson's disappearance questioned hundreds of registered sex offenders and parolees, but decided not to follow up even though they couldn't verify many of their alibis.

Atttorney Mark Geragos (search) repeatedly got the detective to acknowledge that police closed the cases on many of the offenders, marking the files "complete," without eliminating them as suspects.

Geragos continued to tick off more names Tuesday as he worked to create reasonable doubt in the jurors' minds that Peterson killed his pregnant wife.

Under questioning by prosecutors following the cross-examination, Coyle said the goal of making the list was "sort of like, 'Round up the usual suspects.' It was a starting point. ... We had really not much to go on in the beginning and it was suggested that something of this type could have been done by a person who was a convicted felon or a sex predator."

He added that efforts to track down the offenders did not dilute authorities' suspicions that Peterson was the killer.

On Monday, Geragos had quizzed Coyle about one possible suspect whom Coyle said confessed.

"He said he murdered a female named Lisa Peterson, right? ... He said the only witness was the dog ... He said he broke her neck?" Geragos asked Coyle on Monday.

"Yes," Coyle replied.

The man's admission was discounted because he had "severe" mental problems and wasn't on medication, prosecutor Rick Distaso said in his later questioning of Coyle.

Coyle was originally called by the prosecution last week to testify about the extensive search for evidence at the Petersons' Modesto home, but Geragos quickly asked questions about the sex offenders and parolees who lived near there.

The detective said Monday that after police tracked down 285 of the 309 sex offenders and parolees living in the area, they closed most of the files without ruling them out as suspects or confirming many of their whereabouts on Dec. 24, 2002, the night Laci Peterson was reported missing.

Prosecutors allege Peterson murdered his pregnant wife on or around that date, then drove to San Francisco Bay and dumped the body. Peterson acknowledges being on the bay that day, but said he went fishing alone and returned to an empty home. Geragos asserts that someone else abducted and killed Laci, then framed her husband.

Earlier Monday, Detective Henry "Dodge" Hendee testified under cross-examination that residue from seven suspicious stains collected from Peterson's pickup truck were not blood, and that no incriminating evidence was found in a large tool box in the bed of the vehicle.

Prosecutors allege that Peterson used the tool box to conceal Laci's body during the drive from the couple's home to the bay.