MONTGOMERY COUNTY, Md. (WUSA9) -- Montgomery County Police have announced a person of interest in the March 25, 1975 disappearance of the Lyon sisters on Tuesday.

Police named Lloyd Lee Welch Jr. as a person of interest in the girls' disappearance during a press conference at the Montgomery County Public Safety Headquarters in Gaithersburg, Md. He is also known as Michael Welch.

VIDEO: A Look Back at the Lyon Sisters' Disappearance

Investigators say Welch was noticed paying attention to the sisters at Wheaton Plaza the afternoon they disappeared.

The two girls, Sheila Lyon, age 12 at the time, and Katherine Lyon, age 10, left their house to go to a nearby shopping center; the Wheaton Plaza located in Montgomery County, Md.

"It was very scary at the time," recalled Jane Harding, who lives around the corner from the Lyons. Harding has lived there since the 1950s.

She said police did not initially think the girls were abducted.

"They were being treated as runaways so it wasn't as serious, we thought, as children who were being abducted," said Harding.
But soon everything would change - police changed their approach from runaways to abductees and the community changed the way they lived.

"Everyone was afraid to let their children outside to play because these two young girls had just disappeared," said Harding. "It was like having your own child disappear."

Welch is a convicted sex offender and has been in prison in Delaware since 1997, according to police. Police wrote in a press release, "He traveled extensively throughout the U.S. from the 70s through the mid 90s. Welch worked as a ride operator for a carnival company, often set up at malls. He was arrested in several states, charged with sexual offenses against young girls."

Investigators are looking for any help from the public in getting information about Welsh, his associates and activities. They are also looking for people who may be victims who have not come forward.

Please call 240-773-5030 with any information you may have about the incident or Welsh.