Laci Peterson was expected to give birth to a healthy baby boy about six weeks after she vanished, her doctor testified Wednesday at Scott Peterson's double-murder trial

Dr. Esther Tow-Der said Laci's expected due date was Feb. 10, 2003. The couple planned to name the child Conner.

She said she last saw Laci on Dec. 23, 2002 for a prenatal exam, just a day before the eight-months pregnant school teacher vanished.

"The baby was doing fine," Tow-Der said.

Judge Alfred A. Delucchi indicated jurors would likely begin hearing the grim details of medical examinations of the remains of Laci Peterson (search) and the couple's fetus as soon as Wednesday.

On Tuesday, defense lawyer Mark Geragos (search) used a prosecution witness to point out to jurors the lack of physical evidence in the case implicating his client in the murder of his pregnant wife.

Pin Kyo, a state Department of Justice criminalist, testified she found no blood on any of the tattered clothing on Laci's remains that washed up on the shore of San Francisco Bay months after she disappeared.

Kyo said she did find a few specks of blood on a comforter cover from the Petersons' bedroom, but another witness from the same agency — criminalist William Hudlow — later testified that DNA testing indicated the blood came from Scott Peterson (search).

Kyo testified she examined the clothing taken from Laci's remains — including a bra, panties and a pair of maternity pants — and found no blood and no tears to indicate a struggle.

Prosecutors are trying to prove that Peterson killed his eight-months pregnant wife on or around Dec. 24, 2002, then dumped her weighted body into San Francisco Bay.

The bodies of Laci Peterson and her fetus washed up in April 2003 not far from the Berkeley Marina, where Scott Peterson says he launched his boat that Christmas Eve morning for a solo fishing trip.

Kyo said she found a "tangled mass of fibers and tissues" on a strand of duct tape on Laci's body.

Kyo also answered a series of questions about a separate section of duct tape and a large, tarp-like piece of plastic found near Laci's remains. The prosecution maintains that this other tape and tarp were unrelated to the murders, but the defense has implied that they may have had some connection.

Kyo said the duct tape found on Laci's remains did not match duct tape discovered along the rocky bay shoreline near where her body washed ashore, and that she found no tissue or blood on the tarp. She also "didn't smell any rotting tissue," she said.

Kyo said she also tested twine-like material taken from around Laci Peterson's dead fetus' neck. Showing a picture of the twine to jurors, prosecutor Dave Harris asked her about what appeared to be a small loop tied off with a knot.

"The way it's tied is very loosely," Kyo said, supporting the prosecution's position that the dead fetus became entangled in the twine after it was expelled from Laci's decaying body.

Defense lawyers claim someone else abducted and killed Laci, and that the child was born alive and murdered later. They have said that the twine was intentionally tied around the baby's neck.

On cross-examination, Kyo acknowledged that one knot did appear to be tightly tied.

Geragos then walked Kyo through each item she was asked to test for blood, getting her to say repeatedly that nothing was found. He led her back to testimony from Monday when she told jurors she found no blood on two mops and a bucket seized from the Petersons' home. Prosecutors have implied Peterson used the mops to clean the murder scene, but have presented no evidence to support that theory.

"There was absolutely nothing on it, right?" Geragos asked.

"That is correct," Kyo replied.

She acknowledged that no blood was found on a small folding knife, nothing in a toolbox in Peterson's pickup truck that police allege he used to store his dead wife's body in, no blood on two pairs of shoes, on Peterson's boat cover or on numerous articles of clothing.

"All negative for blood, right?" Geragos prodded

"That is correct," Kyo said.

Kyo also acknowledged she found nothing incriminating in the contents of the Petersons' vacuum cleaner, and she seemed puzzled when Geragos prodded her about concrete "chunks" found in Peterson's boat cover.

"Now this is what was called the chunks of concrete, is that correct?" Geragos asked, holding out in his hand the tiny pieces flecked on paper.

"That is correct," Kyo said.

In a display of courtroom theatrics, Geragos then pulled out a small bucket-sized cement anchor Peterson claims he made for his boat.

"Now, that's a chunk of concrete," Geragos said, before asking her whether the tiny flecks of cement appeared similar to the anchor.

Kyo could not say, but Geragos walked slowly in front of jurors with the anchor and the concrete pieces, holding both out for their examination. Jurors leaned forward in their seats and looked closely.

Prosecutors claim Peterson used the rest of an 80-pound bag of concrete to make other anchors he used to weight down his wife's body in the bay, but Geragos has said Peterson used the extra material to fix his driveway. There has been no testimony yet about whether concrete samples taken from Peterson's driveway matched the concrete used to make the anchor.

Later, Galen Nickey, fingerprint expert with the state Department of Justice, testified he was unable to get readable prints from the duct tape found on Laci's remains.