Earlier this week, a jury found Cooper guilty in a string of five killings in 2006 and 2007.
Detectives say he shot the men to cover up a series of robberies throughout the Triangle.
Prosecutors are pushing for the death penalty in the case. They rested their case Friday this morning - but not before three of the murder victims' family members spoke about their lost loved ones.
"Every time he would come home, he would say 'I saw someone who looked just like Tim,' and he just looked for Tim in the crowd everywhere," testified Phyllis Barnwell of her husband.
The couple lost Timothy Barnwell to Cooper.
After holding back their tears all through the initial trial, the families had a chance to share their pain in open court.
Said Carolyn Reed of her cousin Ricky High: "He's not at our family reunions anymore. He's got two nephews he'll never get to see anymore."
Jurors cried openly as they heard about the devastating moment when each family member learned that their loved one had died.
"When David answered through the door I realized he was crying and I couldn't open it from the inside. He couldn't open it from the outside. All we had to do was turn the handle, but we just couldn't seem to. And I screamed 'Where's Timmy?' and he said 'He's gone,'" said Barnwell.
The defense was supposed to start presenting reasons Friday why Cooper should not be sentenced to die, but some witnesses were not able to make it to court. The case will resume on Monday.
Defense attorneys have argued that years of physical and emotional abuse by Cooper's father left him with diminished mental capacity and unable to plan the killings.