A 62-year-old man accused of fatally stabbing the brother of Los Angeles County Supervisor Mark Ridley-Thomas in 1981 has pleaded not guilty to a murder charge.

Michael Anthony Locklin remains jailed without bail and is due back in court March 9, when a date will be set for a hearing to determine if there is enough evidence for him to stand trial.

The murder charge against him includes a special circumstance allegation of murder in the commission of a robbery, but prosecutors have not yet decided whether to seek the death penalty.

He is accused in the death of 37-year-old Michael Thomas, an insurance adjuster. Prosecutors contend Locklin killed Thomas in the victim’s South Los Angeles home sometime between Aug. 13-16, 1981. Thomas’ body was discovered at his residence in the 4600 block of Santa Barbara Boulevard, now Martin Luther King Jr. Boulevard, after he missed church services and failed to show up at work.

Cold case investigators identified Locklin through DNA evidence, according to a District Attorney’s Office spokeswoman who said she couldn’t offer any details about the source of that evidence. She also said she couldn’t elaborate on the nature of the interactions between Thomas and Locklin before the robbery-killing, but said the men knew each other.

Locklin was convicted of rape and other sexual assault offenses in 1987 and is listed as a high-risk sex offender, the Los Angeles Times reported.

Ridley-Thomas was first elected to public office—as a member of the Los Angeles City Council—10 years after his brother’s killing. He served the city for nearly a dozen years before being elected to the state Assembly, where he served two terms. He has been a member of the Los Angeles County Board of Supervisors since 2008.