A hiker found McAllister's remains a year later, police said.
No arrests were made in the two decades since.
The television station is directly adjacent to the police station.
In 1993, 20-year-old Frank Wesley McAlister was killed.
The station did not air his on-camera interview until he surrendered to police.
Hawkins said he seeks forgiveness.
As a result of Hawkins' confession, Redding police immediately searched out and rounded up two of his alleged accomplices: 46-year-old Shanna Culver and her brother, 45-year-old Curtis Culver.
Brian Keith Hawkins, 44, turned himself in at the Shasta County Sheriff's station on Tuesday - and delivered an emotional confession to local news station KRCR. "I know the wrong can't be changed but this is the closest I can come to doing the right thing".
Hawkins and the Culvers were arrested and charged with the murder of McAlister. The trio was booked in the Shasta County jail.
An insurance settlement McAlister received prior to his slaying ― approximately $4,500 from a vehicle accident ― might have been a motive in his death, according to the Redding Record Searchlight.
"Every minute of every day has been a nightmare", Hawkins said.
Detectives knew in 1993 that the three were the last people to see McAlister alive, but Hawkins and the Culver siblings denied any connection with his death.
Investigators say one of the Culvers confessed as well, but did not specify which one.
About a year after McAlister disappeared, a passerby found his body in a rural part of Shingletown, a few miles east of Redding, police said.
The motive was likely a robbery, Redding police investigators told the station. Hawkins continued, saying that there hadn't been a moment where he hadn't been remorseful for what he had done.
He told investigators that he, Curtis Culver, and Shanna Culver lured McCalister to an area near Hawkins's hometown of Shingletown and stabbed him to death. Instead, he was robbed and stabbed to death-his body left to rot and his vehicle dumped at the nearest Costco.
During their interviews with police this week, Hawkins and the Culvers gave different accounts.
Hawkins and Curtis Culver are being held on $1 million bail, while the other Culver sibling is being held without bail.
Curtis Culver, on the other hand, told police that Hawkins did all the stabbing, the complaint says.
After appearing on camera for a tearful interview, Hawkins met with Redding police and gave a statement.
During his TV interview Tuesday, Hawkins, wearing a long-sleeve T-shirt and camouflage trousers and clasping a can of cola, declined to give details about the killing.
"I've been through hell my whole life because of this", Hawkins told the station through tears, saying that he even reached out to McAlister's family past year.