Laci Peterson's head and parts of her limbs were missing and plastic tape was wrapped around the neck of her child, according to the full autopsy and coroner's photographs exclusively seen by ABCNEWS.
According to the autopsy, the skin of the child was not decomposed at all, though the right side of his body was mutilated, and the placenta and umbilical cord were not found with the body.
The autopsy said that the cause of Laci Peterson's death was undetermined, and there was no evidence of man-made wounds, despite the fact that her head and all or part of her limbs were missing.
Peterson's body was so badly decomposed it barely looked like a body after it was found in San Francisco Bay last month. However, the autopsy report showed her cervix was intact.
Experts are divided over whether the new revelations about the condition of Laci Peterson's body and that of her child will help prosecutors or attorney's representing Laci's husband, Scott, who has been charged in the case.
On Thursday, sources close to the investigation told ABCNEWS the sealed autopsy report indicated a piece of nylon tape was looped around the child's neck when it washed ashore last month, and that there was a laceration or tear on the tiny body.
There also was tape on Laci Peterson's lower torso, outside her clothing, when her body was found April 14, a day after her baby's remains were recovered, the sources said.
Forensic pathologist Dr. Michael Baden told Good Morning America that the limbs and head were probably removed before Laci was put in the water.
Baden, the former chief pathologist for New York City, said it could not be determined from the autopsy how the baby came out of Laci's body.
"It does tell us that the baby was in the womb for many months after Laci was in the water and Laci in fact protected the baby until the baby came out shortly before the bodies were found," Baden said.
He said the tape on Laci's body and a cement bag that was found washed up on the shore near the baby could be important evidence.
"If any of that matches cement or duct tape that they've come in contact with in removing stuff from Scott's place of work or place of residence, that's heavy evidence," he said.
Legal experts say that the autopsy leaks, along with recent statements from Scott Peterson's lawyers including one that Laci might have been killed by a satanic cult, could be part of a strategy by the defense to create doubts in the minds of prospective jurors even before the case goes to trial.
"The defense wants to try to get out as much information as possible to instill reasonable doubt that there might be other people involved in this other than their client," said criminal law expert Leonard Birdsong, a professor at Barry University School of Law in Orlando, Fla.
"I haven't been involved in the investigation, but having done some defense work in my time, if you have something that might help you instill reasonable doubt, I would certainly try to float it," he said.
As for the autopsy report itself, it does not have to indicate a cause of death to be a strong piece of evidence in a murder trial, even if it is only one more piece of circumstantial evidence.
"The autopsy doesn't have to have, for instance, a bullet wound in the head in order to know that if somebody threatened somebody, they have done things to them in the past, they make up stories to explain where they were supposedly on the night of the incident, people saw them going to the location, people saw them coming back," said law professor Richard Kling of the Chicago Kent College of Law.
However, because the autopsy does not say how Laci Peterson died, the prosecution will still have some work to do to make their case, he said.
"Somebody is going to have to come in and testify that what caused the death is a-b-c, blunt instrument, stabbing, shooting," he said. "More significantly, somebody's going to have to talk about the manner of death — they're going to have to classify it either as an accident, or a homicide or suicide and they're going to have to do that somehow."
The grisly new details could fuel speculation as to whether the baby ever lived outside the womb, which defense attorneys could use to undermine the prosecution's case against Scott Peterson, Laci's husband and the father of the child they had planned to name Conner.
The prosecutors handling the case said Thursday that since the autopsy was starting to be leaked to the media, the whole report should be released. They filed a motion late Thursday to unseal the autopsy.
Kim Petersen, a spokeswoman for Laci Peterson's family, said on Thursday that the family would trust the prosecutors' judgement about whether the full reports should be unsealed, but they were horrified by the leaks of details from the autopsy reports.
However, Superior Court Judge Al Girolami ruled tonight that both autopsy reports should remain sealed and said releasing the information could prejudice public opinion before the trial.
The judge also indicated that he may issue a gag order preventing both sides from speaking to the media.
While the defense and prosecution dispute what the latest revelations might mean, experts also appear divided.
When asked what the tape on the bodies might mean to the case, Robert Pugsley, a law professor at the Southwestern University School of Law in Los Angeles, told ABCNEWS Radio: "This 8-month-old fetus was the direct intended victim, as well as the mother, of the homicidal activities of the murderer.
"This is a clear indication that the state is perfectly justified — indeed, I think, obliged — to pursue the double-homicide case which they've already laid," he said.
But Dr. Robert Goldberg, a forensic pathologist in Marietta, Ga., said Thursday that there are a lot of unanswered questions involving the tape, making it too early to tell if it means the baby was killed, or who the killer is.
"It could have been picked up as some artifact in the water," Goldberg said. "The child could have been dead before this occurred, and this could just be a connection to keep the child weighted down."
Royal Oakes, a Los Angeles-based attorney, told ABCNEWS the tape revelation could present possibilities for the defense.
"A defense attorney's strategy, faced with this kind of bizarre evidence, is essentially going to be, 'What does this have to do with my client? What evidence is there that Scott Peterson did these things?' " Oakes said.
Prosecutors Dismiss Defense Theories
Laci Peterson, 27, of Modesto, Calif., was eight months pregnant when her husband reported her missing on Dec. 24. Scott Peterson, 30, was arrested April 18 and is being held without bail on two counts of murder. He could face the death penalty if convicted.
Scott Peterson has acknowledged he was having an affair with a massage therapist, but he insists he never hurt his wife or the baby. His attorneys have suggested the pregnant woman may have been kidnapped and killed by a satanic cult. If there was evidence that the baby might have been born, that could be used to support the theory.
But investigators do not believe Laci was killed by a satanic cult, or that her baby ever lived on its own. "The autopsy in its entirety would not leave as much room for speculation," one source told ABCNEWS.
However, a defense source maintained the tape was tied around the baby's neck, the cut on the body appeared to have been made intentionally and the condition of the child was not consistent with a so-called coffin birth, in which a fetus is expelled from the body of a woman who died while pregnant.
ABCNEWS' Chris Vlasto, Taina Hernandez and Mike Gudgell contributed to this report.