Investigators tasked with gathering evidence against Scott Peterson (search) summoned underwater search experts from as far away as New York, but didn't find anything incriminating off the San Francisco Bay shore where the remains of Laci Peterson (search) had surfaced, a detective testified Thursday.

Teams of FBI divers repeatedly trolled the waters starting in mid-May, a month after the badly decomposed torso of Laci Peterson and the couple's fetus washed ashore — and Peterson was charged with murder. They joined underwater sonar operators who had been methodically scanning the bay floor for months.

Defense lawyer Mark Geragos (search) continued his cross-examination Thursday of Modesto police Detective Henry "Dodge" Hendee, who was present for more than a dozen searches after Peterson's arrest.

Hendee didn't cover much new ground — defense lawyers have highlighted the fact that the prosecution has scant physical evidence linking Peterson to his wife's killing.

On Thursday, Geragos repeated his summary that the meticulous, hours-long searches of murky water and rocky shore yielded nothing related to this case.

"You found sticks, you found pipes, all kinds of debris, but you didn't find anything related to this case, right?" Geragos prodded.

"Yes," Hendee replied.

Later, Geragos attacked each piece of evidence authorities collected in their search of Peterson's home and warehouse -- from stained boots to black maternity pants to a boat cover. "And what did you find?" Geragos asked repeatedly.

"Nothing," Hendee replied.

The more than 3,800 sonar scans authorities did fix on 800 potential targets — of which 223 were investigated further. Hendee testified Wednesday authorities were searching for items such as concrete anchors they believe Peterson used to weight down his pregnant wife's body, as well as missing body parts.

Prosecutors allege Peterson murdered his wife in their Modesto home on or around Dec. 24, 2002, then drove to the bay and dumped the body.

Peterson acknowledges being on the bay that Christmas Eve day, but said he went fishing alone. Geragos asserts that someone else abducted and killed Laci Peterson, then dumped the body to frame her husband.

Hendee's testimony came a day after Judge Alfred A. Delucchi (search) said he would entertain a defense motion to dismiss the double-murder on allegations that another detective — a prosecution witness — lied on the stand.

At issue is testimony from Modesto police Detective Allen Brocchini (search ) who defense lawyers assert misstated key details under questioning.

Brocchini testified last month about a tip he received several days after the remains were discovered by pedestrians walking along the rocky bay shore in April 2003.

The tipster alleged that, in 1995, Scott Peterson said he would dispose of a body by sinking it in the ocean. Brocchini testified he didn't consider the information credible and shelved it.

He also said the tipster alleged Peterson would "tie a bag around the neck with duct tape" — a potentially damaging assertion because police said duct tape was found on Laci Peterson's badly decomposed torso.

A source who has heard a tape of Brocchini's interview with the tipster told The Associated Press that the man never mentioned duct tape, implying Brocchini lied on the stand.

The judge set a July 29 date to hear arguments from defense attorneys seeking to have the case dismissed. Delucchi has already rejected two mistrial requests from Geragos during the trial's seven weeks.

Legal experts said a mistrial or dismissal is highly unlikely. But Geragos could benefit if allowed to grill Brocchini about his controversial testimony in this case, as well as a prior instance of on-the-stand misconduct.

All along, Geragos has claimed authorities were determined to get a high-profile conviction at any cost.

Out of the presence of jurors Wednesday, Geragos called Brocchini's testimony an "intentional and willful violation."

Geragos wants to discredit Brocchini even more by trotting out a 1998 home invasion robbery case in Modesto which Brocchini investigated.

Brocchini's testimony caused a mistrial after a Stanislaus County judge ruled his comments about another robbery might have prejudiced the jury, according to court documents.

A defense attorney alleged Brocchini intentionally disregarded the judge's directive not to mention that case because prosecutors "felt the case slipping away," according to an opinion from a state appeals court. The court found Brocchini's conduct to be "improper" but didn't conclude he intentionally tried to "trigger a mistrial."

Chances are remote that Judge Delucchi will grant a mistrial or dismiss charges, speculated Jim Hammer, a former prosecutor who regularly attends the Peterson trial.

But Geragos still may damage Brocchini's credibility — and by association the prosecution's case — if the judge lets him cross-examine the detective about the 1998 case.

"This would be their Fuhrman," Hammer said, referring to the Los Angeles police officer whose false testimony helped acquit O.J. Simpson on murder charges. "That would be like dropping a bomb on the prosecution."