A registered sex offender in Oregon was busted on murder charges after a victim who investigators believe is an 89-year-old missing woman was found dead inside his car, police said.

Timothy Joseph Mackley, 58, was arrested Monday during a traffic stop in Portland after police identified him as a person of interest in the disappearance of Marcine Herinck, who was reported missing Sept. 19, police said.

Officers found the body of a person they believe to be Herinck in the trunk of Mackley’s Toyota Camry. Investigators — who found evidence of foul play in her death — had been unable to locate Herinck during an earlier search of the woman’s neighborhood, including a nearby pond and golf course, police said.

The Oregon state medical examiner has determined that the victim in Mackley’s car died of homicidal violence, but authorities provided no further details.

“The Police Bureau recognizes the importance of providing accurate information as well as information in a timely fashion, however, the process to identify the victim in this case has been complicated,” police said in a news release Wednesday. “The Bureau will provide an update once the victim has been positively identified by the Oregon State Medical Examiner’s Office.”

Herinck’s relatives, meanwhile, have requested privacy, police said.

Mackley, of Portland, is a registered Level 3 sex offender who was convicted of sodomy and sex abuse in 1999, online records show.

Messages seeking additional comment from police were not immediately returned Wednesday. It’s unclear if Mackley, who was set to be arraigned Wednesday, has hired an attorney.