DURHAM, N.C. — After 54 days, testimony is over in the Mike Peterson murder trial. Plus, jurors learn Margaret Ratliff is not biologically related to the Durham novelist.

Police Detective Art Holland testified the prosecution had tested a licked stamp for DNA. It came from a letter sent by Margaret Ratliff, the daughter of Elizabeth Ratliff. Ratliff was Mike Peterson's friend who died in Germany nearly two decades ago.

Prosecutors believe Mike Peterson not only killed his wife, but also Ratliff. After her death, Peterson raised Ratliff's two girls. The DNA test showed no biological link between Peterson and the older daughter.

"Margaret Ratliff was excluded as being the daughter of Mike Peterson, isn't that right?" defense attorney David Rudolf asked Holland.

"That's correct," Holland responded.

Earlier in the day, State Chief Medical Examiner Dr. John Butts said he has conducted over 5,000 autopsies. On Monday, he showed jurors pictures of Kathleen Peterson's head injuries. Butts testified that the seven deep cuts on the back of her head prove her death was not an accident.

Which side did a better job in presenting its case in the Mike Peterson trial? The prosecution The defense

"In my opinion, the number, location and appearance of the wounds are consistent with inflicted trauma," Butts said.

Prosecutors believe Mike Peterson beat his wife, Kathleen, to death, and defense attorneys believe Kathleen Peterson died from an accidental fall from a stairwell.

Defense attorneys said on Monday that Kathleen Peterson may have coughed up blood, causing much of the blood spatter in the stairwell. Butts countered by saying the amount of blood found in Kathleen Peterson's lungs was minimal.

"There is no evidence of any significant aspiration of blood," he said.

Jurors will get an opportunity Tuesday to look at all the pieces of evidence presented in the case. Judge Orlando Hudson and the lawyers will meet outside the jury's presence for a charge conference. At that point, we could find out if District Attorney Jim Hardin will ask for the jury to consider second-degree murder.