Montgomery County police have identified a “person of interest” in the unsolved, 1975 disappearance of the Lyon sisters, a case etched firmly in the memories of longtime county residents.

Sheila Lyon, 12, and her sister, Katherine, 10, left their home on March 25, 1975, to walk to a nearby shopping center, the Wheaton Plaza, and never returned home.

“It’s the biggest break we’ve had in quite some time” in the case, said Capt. Marcus Jones, commander of Montgomery’s major crimes division.

Officials have scheduled a news conference for 12:15 p.m. Tuesday, and said they will name the man they are investigating and release photographs. They described him as a convicted child sex offender who is currently incarcerated.

Detectives believe the man was at Wheaton Plaza on the day the girls disappeared. At the time, the man apparently spent time in different locations in Montgomery County. Investigators will appeal to the public on Tuesday for more information about the person of interest, his associates and his activities.

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