The prosecution witnesses were intended to help bolster the idea that police exhausted all leads in their investigation of Laci's disappearance. Defense attorneys have accused authorities of focussing too quickly on Scott Peterson and ignoring pertinent tips.
Modesto police officer Eric Beffa testified about an anonymous tip police had received in early January that Laci Peterson was being held captive in a rural area of Tracy.
Beffa quoted from a report about the tip: "They have a pregnant woman there and he states he recognizes her to be Laci ... he doesn't want the reward money, he just wants her to be found."
Beffa said he and another officer responded to the area but were unable to find the location described by the tipster.
On cross-examination, defense lawyer Mark Geragos noted the tip also included mention of a van.
Witnesses have said they saw a van with three "dark-skinned" men in the Petersons' neighborhood around the time Laci vanished. It's a detail Geragos has continually brought up in the trial as he works to create reasonable doubt.
Beffa said he met with a sheriff's deputy but was still unable to find the location from the tip.
San Joaquin County Sheriff's Deputy Paul Mears met with Beffa in Tracy and continued to follow the tip after Beffa left, Mears testified.
Mears described a four-day extensive search of the area. They came upon a "compound," described by Mears as a "a bunch of shanties and shacks, old trailers that had been abandoned."
Mears said he had responded to that location before and knew many of the people who lived there were probationers and parolees.
On this call, police found marijuana being grown, but no connection to the Peterson case, Mears testified.
As the double murder trial enters its 15th week, prosecutors are attempting to build a circumstantial case that will convince jurors that Peterson killed his eight-months pregnant wife, Laci, and their fetus.
Prosecutors have yet to show jurors a murder weapon or a cause of death and have no witnesses who saw Peterson do the deed.
In the days following Laci's disappearance, prosecutors say Peterson acted like a guilty man, repeatedly visiting the marina where police allege he dumped his dead wife's body while authorities scoured San Francisco Bay for her remains.
Jurors last week heard a week of testimony from police officers who tailed Peterson between Jan. 3 and Jan. 11, 2003. They say Peterson drove erratically and acted as if he was attempting to elude authorities at times, which they say is not the behavior of an innocent.
Defense lawyers claim Peterson made the trips to the Berkeley Marina — where he launched what he claims was a solo fishing trip the day he reported Laci missing — simply out of concern for his wife, and that his erratic driving was because Peterson thought he was being tailed by reporters.
Prosecutors allege Peterson killed his wife in their Modesto home on or around Dec. 24, 2002, then drove to the bay and dumped her body. The badly decomposed remains of Laci Peterson and the couple's fetus washed ashore in April 2003, not far from where Peterson set out for that Christmas Eve morning fishing trip.
Defense lawyers contend someone else abducted and killed Laci, then framed their client after learning of his widely publicized alibi.
Testimony later this week will focus on mitochondrial DNA evidence, a technique that can be used to determine a link between a hair, for example, and a person. Such a technique is used when the hair does not have a root and brings with it a much lower degree of certainty than the so-called genetic fingerprinting that is widely used in courts.
The evidence is key to the prosecution's case that Laci was on the boat police allege Peterson kept a secret from her so that he could later use it to dispose of her body. A hair that police say is Laci's was found in a pair of pliers on the boat.
Defense lawyers have vigorously attacked the mitochondrial DNA evidence, calling it the unreliable subject of "raging debate" among scientists.
Experts estimate that half the states allow the technique as courtroom evidence, including California.