Analyst Ivy McMillian told jurors that was likely because Cooper's body had been outdoors for some time in summer heat, and any DNA was probably destroyed.
"No DNA profile was obtained from the fingernail scrapings of Nancy Cooper," she said.
Nancy Cooper's husband Brad is accused of murdering her. Nancy's partially clothed body was found by a man walking his dog in an undeveloped subdivision not far from her home on July 14, 2008 - two days after she was reported missing. She had been strangled. Prosecutors say Cooper killed her because he was angry she intended to leave him, take their children, and move to be with her family in Canada.
The fingernail evidence is of note because detectives have testified they saw scratch marks on Brad's neck when they spoke with him July 12. The prosecution alleges that Nancy was strangled sometime after she returned with Brad from a party in their neighborhood the night of July 11. Brad told detectives his wife went out for a run the morning of July 12 and never returned.
In court Wednesday, McMillian also testified that there was no evidence Nancy Cooper was sexually assaulted. McMillan also examined the liner of the trunk of Brad Cooper's vehicle and a rug from the couple's home. She was not able to develop evidence from either item.
Cooper's defense attorneys have said that police focused on Brad from the beginning of their investigation and ignored evidence that may have pointed at another suspect.
The prosecution has yet to present any physical evidence linking Cooper to the crime. Several former friends and neighbors have testified that he had affairs and that the marriage was deeply troubled. They also said Cooper was acting strangely the day Nancy was reported missing.
The Coopers relocated to Cary from Canada in 2001 when Brad Cooper took a job at Cisco Systems in Morrisville. He studied computer science at the University of Calgary and took graduate business courses at North Carolina State University.
Nancy Cooper's parents now have custody of the couple's two children in Canada.