Doctor: Kathleen Peterson May Have Been Lying In Pool Of Blood For Hours Before Death

Ratliff was Mike Peterson's friend who died in 1985. She was found dead at the bottom of a stairwell in Germany. Prosecutors say her death is similar to that of Mike Peterson's wife, Kathleen, who was found at the bottom of a stairwell in Durham on Dec. 9, 2001. Peterson is charged with his wife's death.

Neuropathologist Dr. Thomas Bouldin told jurors one particular item stood out when he examined Kathleen Peterson.

"This brain had experienced a period of decreased blood flow approximately a few hours before death," he said.

Bouldin believes Kathleen Peterson was lying in a pool of blood for hours before she died. He also said the deep cuts to the back of her head indicate she had been attacked.

Another neuropathologist, Dr. Aaron Gleckman, described the seven gashes found on the back of Elizabeth Ratliff's head. Gleckman said in his opinion, Ratliff died from blunt-force trauma to the head.

The original autopsy showed Ratliff died from natural causes -- a brain hemorrhage -- but Gleckman told jurors a recent autopsy done in Chapel Hill revealed Ratliff had seven gashes on the back of her head, the same number found on Kathleen Peterson's head.

In cross-examination, defense attorney David Rudolf tried to zero in on Ratliff's original autopsy.

"Did you know, for example, witnesses who were in Germany and people who she talked with reported that she had had a very, very severe headache the Thursday before she died?" Rudolf asked.

"I didn't know that, but that doesn't change my opinion about the cause of death," Gleckman said.

Candace Zamperini, Kathleen Peterson's sister, is expected to continue her testimony Wednesday. The state medical examiner is also expected to take the stand.