Cooper didn't testify in person. Instead, jurors saw a video of his deposition filmed in late 2008 when his late wife's parents were trying to win custody of the Cooper daughters.
Brad is charged with killing Nancy Cooper in July 2008. Her body was discovered next to a storm water retention pond in an unfinished Cary subdivision July 14 - two days after she was reported missing. An autopsy showed she was strangled. Cooper told detectives that his wife went out for a run the morning of July 12 and never returned, but prosecutors allege Brad killed Nancy the night before because he was angry she planned to divorce him and move with their two daughters to Canada.
The wide-ranging deposition video covers everything from Cooper's affair with a friend of Nancy's to the couple's finances.
Cooper told the lawyer asking questions that he initially denied the affair with Heather Metour.
"I thought if I told her about it, it would ruin our family," he said.
Brad said he later admitted the affair and told Nancy it was a mistake.
Later in the interview, Cooper was asked if Nancy had any weaknesses.
"She spent more than we had which is unfortunate. And she drank a little bit more than I would have wanted to," he said.
Cooper said he put Nancy on a cash budget of $300 a week because of her spending habits and she referred to him as "The Budget Nazi."
One of Cooper's chief alibis is a phone call that came from the Cooper home to his cell phone the morning Nancy was reported missing. Brad told detectives Nancy called him during a trip to the grocery store to tell him to pick up extra items. That goes against the prosecution's contention that Nancy was already dead when the call was made.
The prosecution says Cooper had the technical knowledge - as a phone system expert at Cisco - to fake a call from his home. He was asked about that during the deposition.
"Do you have personal knowledge as to how to initiate a call from a remote location?" asked attorney Alice Stubbs. "Some of our software can do that, yes," said Cooper.
Nancy told friends that Brad was acting strangely and was depressed before her death. Stubbs dug into that in the deposition.
"Have you ever considered taking your own life?" said Cooper.
"Yeah," Cooper responded.
Cooper said Nancy had a $75,000 life insurance policy, but that he had not tried to claim the money.
"Given the circumstance and everything else, I didn't think it was appropriate," he said.
Cooper was also asked about a draft separation agreement between Nancy and himself that he never agreed to. Cooper said he calculated that it called for him to pay between five and six thousand dollars per month.
"Is that more than you make at Cisco?" asked Stubbs. "After taxes, yes," Cooper responded.
Cooper also admitted that he took his daughter's passports out of Nancy's car to keep her from leaving the country with them. He said when Nancy asked for them back, he told her that each of them could have one.
Cooper said Nancy had plans to run July 11 with a friend but cancelled them. He said she instead ran July 12.
"She left the house at about 7 a.m.," he said.
Cooper testified that he didn't see Nancy leave the house. He said when she hadn't returned by midday, he began to get worried and called some of Nancy's friends looking for her. He then loaded his daughters in the car and began driving around looking for her.
Around 2 p.m., he said he got a call from Cary police because one of Nancy's friends had reported her missing.
Coopers 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. Nancy's family did win custody of the Cooper children. They now live in Canada.