RED LODGE, Mont. (AP) — Montana authorities said Tuesday that human remains found in Carbon County about 18 years ago have been identified as those of a Wisconsin hitchhiker who left his home state to flee legal trouble.

The Carbon County Sheriff’s Office said the remains of Rogers Lee Ellis were identified after state and federal agencies launched an extensive genealogy investigation this year. The investigation included sending skeletal remains to Othram, a private DNA lab in Texas, which used its technology to build a DNA profile that ultimately helped identify the remains.

Now, authorities say they are turning their investigation to finding Ellis’ killer.

Ellis was born in Wisconsin Rapids in 1954. The Carbon County Sheriff’s Office said that in December 1976, he was facing legal issues related to an arrest for marijuana possession. Authorities say he told his family he didn’t want to go to jail and was heading west. He had no further contact with his family.

Authorities believe Ellis was hitchhiking and was killed by one or more traveling companions, who left his body in Montana and continued on their way, the Carbon County Sheriff’s Office said.

Ellis’ remains were discovered in June 2004 after a hiker found a skull near Red Lodge, off of U.S. Highway 212. Search teams then found a femur and pelvic bone and authorities determined the remains came from the same person. At the time, DNA was entered into a national index, but no match was found until the new DNA profile was built this year.

Authorities are asking anyone who knew Ellis in the 1970s or might have information about his death to come forward.