Brian Hawkins told KRCR in Redding that he and two accomplices robbed and killed 20-year-old Frank Wesley McAlister, whose slaying was unsolved for nearly 25 years.
The 44-year-old Hawkins refused to give any details about the killing in Tuesday's interview but said living with the secret had been "absolutely horrible." He said he wanted people to know he was remorseful.
After the interview, Hawkins went to the Shasta County Sheriff's office to meet with investigators.
Redding Police say Hawkins, 45-year-old Curtis Culver and Culver's sister, 46-year-old Shanna Culver, have been arrested in the case.