Officers said when they arrived at the apartment, 45-year-old Darryn Maurice Dye was unresponsive. He was declared dead at the scene by Orange County EMS workers.
A woman who told ABC11 that she was Dye's sister said the couple had a stormy nine-year relationship and Dye was staying at her apartment when things unraveled.
"I said, 'Here comes your wife,' and he thought I was joking," Angela Gilmore said. "When she came inside the house and everything, they got to ... arguing, talking back and forth to each other and I was like, 'Y'all just need to chill out.'"
Gilmore said they then started eating.
"I thought she was going in the kitchen to get a cup and next thing I know, he was standing by the door," Gilmore said. "She went in there and did like that and when she did like that to him, he just fell out."
Gilmore said that's when she saw a knife and they tried to do CPR on Dye.
"I started smacking him on his face and I was like, 'Wake up bro, wake up,' and the only thing I saw when he looked straight in my eyes and he did like that, I knew he was already gone."
McClinton, of Ashley Forrest Road in Chapel Hill, has been charged with first-degree murder.
Police said the investigation is ongoing.