"We found out, uh, late that Sunday afternoon. The CCU nurse came out crying and said that, uh, the pressures in his head had gone up too far. They couldn't do anything else," he testified.
Ring's son Kenny was the manager at a Knightdale Domino's Pizza restaurant in January, 2010 when he was beaten and robbed.
Prosecutors allege it was an inside job pulled off by one of the store's drivers - Nico Bowers - and his friend Travis Sherman.
Sherman is currently on trial.
On Monday, another driver recalled seeing Bowers and Sherman together in Bowers' car on the night of the killing. He testified that was unusual because drivers were not supposed to carry passengers on deliveries.
Prosecutors say they believe Sherman attacked Ring with a metal baseball bat. The alleged weapon has never been recovered.
Also Tuesday, Sherman's former girlfriend testified he asked her to give him an alibi. She said he wanted her to tell police that they were together on the night of the murder, but she said they had broken up long before and were not together.
"He asked me if I would lie for him and say that I picked him up at 11 o'clock that night," said Anna Painter.
Sherman's attorney says he's innocent and claims Knightdale police botched the investigation. He pointed out on Monday that his client's fingerprints were not found at the crime scene.