Montgomery Police Chief J. Tom Manger, left, and Special Agent in Charge of the F.B.I. Baltimore Field Office, Steve Vogt, right, leave a February news conference behind a mugshot of Lloyd Lee Welch. (Ricky Carioti/The Washington Post)

Lloyd Lee Welch, a Delaware inmate identified as a “person of interest” in the notorious disappearance of two young girls in Montgomery County 39 years ago, has been denied early release from prison, Delaware officials said Thursday.

Welch, a convicted sex offender, had sought to have his sentence commuted by the state’s Board of Pardons, but it denied his request ahead of a meeting Thursday, said Matthew Hartigan, acting spokesman for the Delaware Department of State.

In 1998, according to court records, Welch pleaded guilty to sex offenses in Delaware. His release date is set for June 2026, according to Delaware records.

More than two decades before Welch was convicted in the Delaware case, Sheila Lyon, 12, and her sister Katherine, 10, vanished after walking from their home in Wheaton, Md., to a nearby mall. Their 1975 disappearance sparked a massive search.

This year, Montgomery County police officials announced that they had identified Welch as a “person of interest” in the case.

Montgomery County Police Officer Robert Ladany uncovers mug shots of Lloyd Lee Welch at a news conference in February in Gaithersburg. (Ricky Carioti/The Washington Post)

Officials said he was at Wheaton Plaza the day the Lyon sisters went missing and had seemed to pay special attention to them.

Welch, 57, has denied having anything to do with the girls’ disappearance.

In Delaware, offenders can receive credit off their service for good behavior, and it appears that Welch — who originally was sentenced to 33 years — has benefited from that. But many years ago, the state abolished parole for offenses committed after June 1990.

Inmates can still seek a change in their sentence through a three-step process known as commutation.

According to officials, it involves hearings before the Board of Parole, the Board of Pardons and — if it gets past those boards — a review by the governor.

Law enforcement officials in Montgomery declined to comment on the development in Delaware. Investigators continue to work hard on the case.

Longtime residents remember the famous case well. Relatives of the Lyon sisters still await some kind of resolution.

“The family deserves justice,” Montgomery Police Chief J. Thomas Manger said earlier this year.

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