Defense attorneys for Scott Peterson have begun their counterattack, starting with a concrete expert whose testimony poked holes in a prosecution theory that Peterson used concrete anchors to weigh down the body of his pregnant wife.

Prosecutors claim Peterson made five cement anchors, one of which was found in the boat they allege he used to dispose of his wife's body in San Francisco Bay (search). The others have not been found.

Peterson told police he made only one anchor and used the rest of the 90-pound bag of cement to repair his driveway. A prosecution witness testified earlier that concrete samples taken by police from Peterson's driveway were not from the same mix as the anchor.

But in testimony Monday, defense witness Steven Gabler (search) said they were indeed a match with the anchor. Gabler, a concrete expert, was asked to examine samples taken from Peterson's driveway.

Defense lawyer Mark Geragos (search) also asked if Peterson had anything to gain financially from the deaths of Laci or the fetus.

Martin Laffer, a certified public accountant and former Internal Revenue Service investigator, testified Monday that Peterson's start-up fertilizer business was indeed faltering, but that the parent company assumed all the debt, and in fact, had planned to lose money for the first four years.

Laffer then said the Petersons appeared in good financial shape.

"There was all this money that was sitting out there and with one or both of their demise, those funds would not be available to them," Laffer said. "From a financial standpoint, he would have been better off if they were alive."

Peterson is accused of killing his wife, Laci, on or around Dec. 24, 2002, then dumping her body in the bay. Her remains and the fetus she carried washed up about four months later, a few miles from where Peterson claims to have been fishing alone the day his wife disappeared.

Defense lawyers contend someone else abducted and killed Laci, then framed their client after learning of his widely publicized alibi.

Also Monday, Judge Alfred A. Delucchi denied a defense motion to dismiss the double-murder charges against Peterson.

Peterson's attorneys are expected to take up to eight days to present their case, with closing arguments planned for Nov. 1. Testimony was expected to resume Tuesday.

In other developments, there were signs defense attorneys were preparing Peterson for possible testimony.

Attorney Michael Cardoza, a former prosecutor who has sat in on the trial as a legal analyst, said Monday he was asked by the defense to cross-examine Peterson in two mock sessions last week.

But, "I gave him no advice," said Cardoza, who added that he took no money for the work.