Pearson - a former friend and neighbor of the Cooper family - admitted he had a sexual encounter with Nancy in late 2005, but said he didn't remember them having intercourse.
Brad Cooper is charged with first-degree murder in his wife Nancy's death. She was last seen alive by friends at a neighborhood party in her Cary subdivision the evening of July 11, 2008.
Cooper told detectives his wife returned late that night and went out for a run around 7 a.m. the next morning, but never returned. Her body was found by a drainage pond in an unfinished subdivision a few miles from her home two days later. The medical examiner said she had been strangled.
Much of testimony in the trial thus far has centered around the Cooper's relationship. Brad has admitted to having an affair with another woman and the prosecution has hinted at more. In its opening statement, the defense brought out Nancy's relationship with Pearson and even questioned the paternity of the Cooper's youngest daughter.
The child "was born eight months and 24 days after he and Nancy were together," said attorney Howard Kurtz.
But Pearson said he and Nancy discussed the timing of her pregnancy and she told him he was not the father.
"We both agreed that we didn't remember intercourse," said Pearson. "We didn't believe that we had gone to that extreme."
On the stand Tuesday, Pearson also referred to Heather Metour as an ex-girlfriend. Metour is the woman that Brad Cooper has admitted to having an affair with, and she was also the subject of an alienation of affection lawsuit brought by Pearson's ex-wife Kinde Rawlins.
In his testimony Tuesday, Pearson said that lawsuit prompted a meeting between him and Nancy in May 2008. He said Nancy wanted to talk about the lawsuit and what happened between them in 2005. Pearson said they mutually agreed not to get involved in the lawsuit and also talked about the Cooper marriage and Nancy's plans to divorce Brad.
A tape of an interview Cary police did with Pearson was also played for the jury. Pearson did not mention the 2005 sexual encounter with Nancy in his first meeting with detectives.
"Once asked about it in the second interview, I answered it completely," said Pearson on the stand Tuesday.
Pearson said he avoided mentioning it the first time around to protect Nancy's memory and to protect his children. He said he didn't think a one-time incident that happened three years before was relevant to the investigation and he was aware it was a very public case and that it would end up in the media.
Prosecutors rested their case last week. They allege Brad killed Nancy because he was angry she planned to divorce him and move with their two daughters to Canada.
Cooper's lawyers say he is innocent and have characterized the investigation by the Cary Police Department as inept. They say detectives focused on Cooper from the beginning of their investigation and never looked at other suspects.
The defense said Tuesday that because Pearson changed his statement about his relationship with Nancy, that police should have been more suspicious of him.
"That's investigation 101," said Kurtz while speaking before Judge Paul Gessner outside the presence of the jury.
On the stand Tuesday, Pearson was asked to go through his 2005 encounter with Nancy step-by-step.
Pearson said it happened after a Halloween party and they were both intoxicated. He said he recalled that they were both naked on a couch, but he didn't recall much more. He said he and Nancy "decided to never speak about it again" in a phone conversation the day after it happened.
Pearson said he had limited contact with Nancy after the incident and that they didn't speak much. But the defense produced phone records that showed more than 10 phone calls made between Pearson and Nancy between early May and the middle of June 2008 and phone records that showed a series of phone calls between the two in May 2007.
Pearson said the calls in 2008 were of limited substance. He said the calls in 2007 came after Nancy confirmed that Brad had the affair with Heather Metour.
He also said besides the May 2008 meeting, and bumping into her at a grocery store in June, he didn't see Nancy. Pearson said he has an alibi for the night prosecutors say Nancy was murdered. He was at his apartment with Heather Metour.