DURHAM, N.C. — Broken cartilage in Kathleen Peterson's neck suggests that someone attempted to strangle her, but the wife of novelist Michael Peterson -- now on trial for her murder -- actually died from blunt trauma wounds to her head, a medical examiner testified Thursday.

Forensic pathologist Deborah Radisch offered the testimony outside the presence of Michael Peterson's jury in support of the prosecution's request to present evidence about another death 18 years ago in Germany.

Radisch said that her review of Elizabeth Ratliff's body, exhumed in April at the prosecution's request, found seven severe laceration in her head that were consistent with a beating.

Judge Orlando Hudson Jr. may rule Friday on whether the deaths of Kathleen Peterson and Elizabeth Ratliff were similar enough that the evidence is relevant for jurors to hear.

The defense insists that while Kathleen Peterson, the defendant's dead wife, and Ratliff were found dead at the bottom of flights of stairs eighteen years apart,  there is nothing similar about their deaths.

Ratliff's sister, Margaret Blair of Warwick, R.I., testified Thursday that she could not get over the similarities between the two deaths when Ratliff's eldest daughter, Margaret, told her how Kathleen Peterson died on Dec. 9, 2001.

Margaret Blair also testified outside the jury's presence Thursday.

Although Blair had hoped to raise Margaret and her younger sister, Martha, Ratliff had specified in her will for Michael Peterson and his first wife to become guardians of the children.

Ratliff was found dead in her home on Nov. 25, 1985, by nanny Barbara Malagino. According to a document submitted by the prosecution, Michael Peterson told Blair "There's been an accident. Liz fell down the stairs and died."

The document also revealed that Peterson had told Blair that after her sister had dined with his family the night before her death, he had escorted Ratliff home to help her put the children to bed and take out the trash.

German police and U.S. military investigators wrote reports about Ratliff's death, but very little investigating was done at the time. A spinal tap conducted at the scene that detected blood in Ratliff's spinal column, leading a German physician to conclude that she had suffered a cerebral hemorrage and fallen down the stairs.

The amount of blood found around Ratliff wasn't questioned, at least not officially. After the jury was sent home for the day, Blair testified that the former nanny had expressed suspicions of foul play to her in 1991. Blair said she told the nanny "God only knows why," but made notes at the time and saved most of them.

"I want answers now," Blair said, breaking down in tears. "I want the truth to come to light. There is so much darkness ... It is time. It is time for the truth. As painful as it is, it is time for the truth to come forward."

Ratliff's other sister, Rosemary Kelloway, cried as she watched the testimony in the first row of the courtroom. Kathleen Peterson's sister, Lori Campell, put her arms around Kelloway and tried to console her.

Blair only learned after Kathleen Peterson's death that her sister's death also included an unusual amount of blood. Moreover, Blair said that Michael Peterson had told her a very different story back in 1985.

"Michael said it was just a little blood behind her ear," Blair testified. "I did not picture my sister laying there in a pool of blood."

As part of the hearing, prosecutors introduced Radisch's two autopsy reports. She examined Kathleen Peterson's body on Dec. 10, 2001. She performed an autopsy in April this year on Ratliff's body after it was exhumed at the prosecution's request.

Radisch testified that the deep, 2 1/4 inch-long laceration on the top of Ratliff's head was in such a position that it mostly likely could not have come from striking a surface.

"I think it would have been unlikely that would have been caused simply by a fall on a stair," Radisch said.

A fall on stairs might have produced the linear skull fracture or one of the multiple lacerations that Radisch described as "severe wounds" found on Ratliff head. But they were unlikely to produced collectively by such a fall.
 
"It is the multiple lacerations and multiple planes that were ultimately significant to you in reaching your opinion in this case?" defense lawyer David Rudolf asked.

"Yes," Radisch said. "I think they are severe wounds."

"What you basiscally concluded was that Ms. Ratliff's death was inconsistent with a fall?" Rudolf asked.

"Yes," she repeated. "There's no doubt in my mind that the blunt trauma of the head, by whatever mechanism, killed her."

Under further questioning, Radisch acknowledged that she could not tell from the autopsy she performed whether Ratliff, 43 at the time of her death, had suffered a stroke. Radisch explained that part of Ratliff's brain was missing when the body was exhumed, and may have been removed in the course of her original autopsy.

Turning to Kathleen Peterson's autopsy, Radisch was asked by Rudolf about broken cartilage in the left side of her throat.

"It is an injury that requires a direct trauma to the area to cause that fracture," she said. "I think it is very likely an attempt at strangulation was made."

Rudolf did not challenge the opinion but tested how deeply a conviction the witness had.

"Can you say that to a certain degree of medical certainty?" he asked.

Radisch said she could.

When the proceedings resume at 9:30 a.m. Friday, the defense will argue that the two deaths are too dissimiliar for evidence about Ratliff to be allowed into the case. If Hudson disagrees and allows the evidence, the prosecution will call witnesses from Germany to testify in front of the jury.

The defense has yet to finish its cross examination of blood spatter analyst Peter Duane Deaver, but the witnesses from Germany have tickets for flights home already.

The trial is being broadcast by Court TV.