BOULDER, Colo. — Colorado investigators are asking for help finding a man suspected of killing Sid Wells, a 22-year-old college student who was dating actor-director Robert Redford's daughter when he was shot to death three decades ago.

Boulder police issued a statement Wednesday saying they're looking for Thayne Smika, who is still being sought after a murder warrant was issued for his arrest in 2010. They're seeking the public's help on the 30th anniversary of Wells' death.

Wells' brother found his body Aug. 1, 1983, in Wells' condominium. He had been shot in the head with a shotgun.

The case attracted worldwide media attention when Redford halted production of "The Natural," being filmed on location in Buffalo, N.Y., and came to Boulder for Wells' funeral.

Wells and Redford's daughter Shauna, then 22, were both students at the University of Colorado and lived in the same building.

Smika, who was often late with rent, was supposed to pay Wells the day he was killed, investigators said.

Police suspected Smika, Wells' roommate, and arrested him a few months after investigators said they linked him to the murder. Smika was never prosecuted because the district attorney at the time declined to take the case.

Smika left the area, and in 1986 his abandoned car was found in Beverly Hills, Calif.

Wells' mother, June Menger, said Thursday that Boulder investigators have been dogged in their work to solve the case.

She said she isn't bitter about the delays in getting a murder warrant. Prosecutors at the time of the killing lacked the evidence techniques that have since allowed detectives to link shotgun pellets recovered from Wells' body to shells found at the Smika family residence in Akron, Menger said.

She said Robert Redford and her son were friends, and they went jogging and skiing together.

She said Redford initially decided not to attend the funeral, worried it would become a media circus. But he decided to come anyway because of his close friendship with Wells.

"He said it had turned into his nightmare too," she said.

Redford said in 1997 that Wells' murder still haunted him.

"It's like a partially opened door with a very dark room behind it," he said.

In 2010, the Boulder County district attorney's office agreed to review the case and approved an arrest affidavit for Smika. But authorities could not find him. Smika's bail was set at $5 million after the warrant was issued.

Boulder Deputy Police Chief Dave Hayes, one of the first detectives to investigate the case, said Smika may have become assimilated into a community and he hopes new coverage of the case will lead a neighbor or a relative to step forward.

"It's time for justice," said Hayes, who has remained in touch with Wells' family over the last three decades.