The jury began deliberating about 4:30 p.m. Tuesday and worked all day Wednesday. They returned Thursday morning and indicated to Judge Paul Gessner that they planned to take a two hour lunch break.
Cooper has been jailed since October 2008, when he was charged with murdering his wife.
Nancy Cooper, 34, disappeared on July 12, 2008. Her husband said she went out for a jog and never returned. Her body - clad only in a sports bra - was found in an unfinished Cary subdivision less than three miles from the couple's home.
In Tuesday's closing arguments, defense attorneys hammered repeatedly on what they called a lack of hard evidence linking the defendant to his wife's death.
"No blood, no bodily fluids, no fibers," attorney Robert Trenkle said.
Cooper's second attorney told jurors Tuesday that Cary police detectives failed in the basic rules of investigation while trying to find his wife's killer.
Howard Kurtz said investigators did not dispassionately gather and evaluate evidence, and instead fit evidence to their theory that Cooper was the killer.
"They considered rumors, gossip, and hearsay as fact," he said. "Justice was sacrificed on the altar of vengeance."
"This case is filled with mighta-beens, coulda-beens and shoulda-beens," Trenkle complained.
Trenkle pointed out several instances where evidence and testimony presented by prosecutors depended more on inference than science to connect it to the crime. He mentioned tire tracks and footprints found near the victim's body, as well as dirt and straw found inside the Cooper's Lochmere home. All were examined, but none directly linked Cooper to the murder scene, Trenkle said.
Prosecutors raised a number of questions about Bradley Cooper's actions based on examinations of the couple's computers and phones, including the possibility that the Cisco-certified voice-over-internet specialist arranged a fake phone call to his cell phone to try to prove Nancy Cooper was still alive when prosecutors contend she was dead.
The defense says Cooper did not have the necessary equipment to make the call. But prosecutors say he did, and he faked the call.
Prosecutor Boz Zellinger pointed out that Cooper had the expertise to even create a special phone number in France so he could talk to a woman he met there.
"If the defendant can create a phone number out of thin air to talk to a woman in France, you think he can fake a phone call?
Prosecutors contend that Cooper planned his wife's death in advance, citing an analysis of Cooper's home computer that shows someone viewed a Google Earth map of the site where his wife's body was found the day before she disappeared.
The defense tried to undermine the evidence about the Google map search, saying there was clear evidence Cooper's computer was tampered with.
But in his closing, Zellinger scoffed at that theory. He said during the same time period, Cooper also went to secure banking websites where he was required to log in, proving he - and not a hacker - was using the computer.
Zellinger told the jury that the case was more "about the defendant's actions" than about hard evidence. He said Cooper repeatedly lied to police and lied in a sworn deposition.
"Why is the defendant lying about where he was the day before his wife was murdered?" asked Zellinger.
Prosecutors allege Brad killed Nancy because he was angry she planned to divorce him and move with their two daughters to Canada.
Several of Nancy Cooper's friends testified about trouble in the Cooper marriage, including signs that Brad Cooper has a controlling personality. He put Nancy Cooper on a weekly "allowance," and monitored her phone calls and email, witnesses testified.
"Two little girls will never see their mother again because of that man," Zellinger told the jury.
The Coopers were newlyweds when they moved to Cary from Alberta, Canada, in 2001 for Brad Cooper to take a job at a high-tech firm in Research Triangle Park. The couple had two daughters while living in North Carolina. Bella and Katie Cooper have been living in Canada with Nancy Cooper's relatives since shortly after their mother disappeared.
The jury has the choice of first-degree murder, second-degree murder, or not guilty.