WASHINGTON — Patricia Welch, the wife of the man investigators have called a person of interest in the investigation into the disappearance of the Lyon sisters in 1975, has entered an Alford plea to a perjury charge in Virginia.

In an Alford plea, a defendant does not admit guilt, but acknowledges that prosecutors have enough evidence for a conviction.

Patricia Welch is the wife of Richard Welch, whom police have described as a person of interest in the disappearance of Sheila Lyon, 12, and Katherine Lyon, 10, while they were walking to a shopping mall in Wheaton, Maryland, in March 1975. He has not been charged, however.

Mark Segraves, of WTOP’s news partner, NBC Washington, broke the story, and told WTOP Tuesday morning that Welch was given a two-year suspended sentence in the rural Virginia county and fined $1,000.

Segraves adds that Bedford County Commonwealth’s Attorney Wes Nance told the court that prosecutors have phone records and audio recordings of Patricia Welch telling witnesses not to cooperate with those investigating the girls’ disappearance — something Welch denied doing when questioned by a grand jury in December 2014.

Patricia Welch’s daughter, Patricia Ann Welch, told NBC Washington that her mother “simply told people they didn’t have to talk to anyone they didn’t want to talk to.”

Lloyd Lee Welch, Richard Welch’s nephew, was charged last year with first-degree murder in the girls’ deaths. Three other members of the extended family have been charged with perjury or obstruction of justice.