On Wednesday, a Dallas Police Department detective identified the voice of the male from Cook's chilling 911 call as Delvecchio Patrick.
Cook was allegedly on the phone with 911 when she was murdered.
Patrick's voice can be heard saying, "I'm gonna kill you! I'm gonna kill you!"
The detective and long-time friend of Patrick, Derick Chaney, was the final witness for the prosecution before they rested Wednesday afternoon. The trial is set to resume Thursday with the defense presenting its case.
Patrick is on trial for the brutal murder of Cook two and a half years ago. He has pleaded not guilty,
A Metro PCS representative testified that Cook called 911 at 10:52 a.m. the day she was killed. The call lasted about 17 minutes.
A 911 dispatcher called Cook's cell phone three times between 11:10 and 11:50 a.m.
Subsequent calls to her phone were picked up by a cell tower near Patrick's father's home.
Further testimony Wednesday revealed a history of violence and abuse in Cook and Patrick's relationship.
A Balch Springs police officer recalled a 2009 assault by Patrick against Cook.
A witness and friend of Cook's said she saw Patrick choke Cook and threatened to do the same to her.
In 2010, there was another incident at Cook's Cedar Hill home. Photos showed a crime scene filled with blood and broken items.
Cook allegedly ran to a neighbor's home covered in bruises exclaiming, "He's trying to kill me! He's trying to kill me!"
Although Cook's face and body were badly beaten, she was arrested for stabbing Patrick in what prosecutors say was an act of self-defense.
Another 911 call was placed by Cook on July 28, 2012.
She asked for help but said she didn't want the cops to come to the door because it would trigger Patrick if he knew she called.