Three relatives of Richard Welch — the Maryland man named a person of interest in the 1975 disappearance of Sheila and Katherine Lyon from a Wheaton shopping mall — were charged Friday with obstruction of justice or lying to a grand jury that is investigating the case here.

The aggressive moves by prosecutors showed how they continue to put pressure on Welch, 70, and his family members. In December, Welch’s wife, Patricia Jean Welch, was charged with lying to the grand jury. Her case is pending.

“Our duty is to get to the truth in this. We cannot do that if we are obstructed or lied to,” said Randy Krantz, the top prosecutor in Bedford County, which is in central Virginia about 200 miles from Washington.

For nearly four decades, the disappearance of Sheila and Katherine Lyon remained one of the D.C. region’s most heart-wrenching mysteries. The sisters — ages 10 and 12 — had walked to the Wheaton Plaza shopping mall in Montgomery County to look at Easter decorations and see friends.

Over the past two years, according to police affidavits filed in court, Montgomery detectives have come to believe that one or more members of the Welch family — with roots in Maryland and Virginia — abducted and killed the girls, and burned their bodies on a rugged section of Bedford County known as Taylors Mountain. A grand jury here also has been investigating the case since last fall.

From left: Amy Welch-Johnson, Leslie Engelking and Gladys Stangee (Bedford Adult Detention Center)

Thus far, one member of the Welch family — Lloyd Lee Welch — has been charged directly in the girls’ disappearance. He was indicted last month and faces two counts of first-degree murder.

Authorities also have labeled one of his uncles, Richard Welch, a “person of interest” in the case. The retiree has not been charged and maintains his innocence. His daughter has called the investigation a witch hunt.

The three cases brought Friday, according to court records and officials, were filed against Leslie Engelking, Richard Welch’s brother-in-law, who was charged with perjury, a felony; Amy Welch-Johnson, Welch’s granddaughter, who was charged with obstruction of justice, a misdemeanor; and ­Gladys Stangee, Richard Welch’s sister, who was charged with obstruction of justice, a misdemeanor.

All three testified before the grand jury Friday. The proceedings are closed to the public. But at various points Friday afternoon, they were led out of the courthouse by sheriff’s deputies to be processed at the Bedford County jail. The three were released on bond or on their own recognizance, Krantz said.

Engelking and Welch-
Johnson declined to comment. Stangee could not be reached for comment.

There was no indication that any of the three had anything to do with the abduction of the Lyon sisters or their killing. Krantz declined to say specifically how they had impeded the investigation. But the prosecutor offered general comments inside the courthouse: “Each of these witnesses made material false statements before the grand jury or obstructed the duties of the law enforcement officers by making false statements. . . . In this case, the grand jury is not going to tolerate people lying to them on issues that are material to these proceedings that prevent us from getting to the truth.”

One of those charged, Amy Welch-Johnson, had not been born at the time of the abduction. Last month, detectives searched her home in Anne Arundel County, looking for records of online communication between her and other family members, according to court records. It was unclear what they took from the home. But authorities have made no secret that they are trying to learn what Welch family members have told one another over the past year as the investigation has heated up.

It was in 2013 that Montgomery County cold-case detectives locked in on Lloyd Lee Welch, who lived in Maryland in the 1970s. His name was in old police case files, but back in 1975, detectives appeared to have been classified as an unreliable witness rather than a suspect. The more the detectives dug into him, the more suspicious they became — in no small part because of what he had done after leaving Maryland. He was convicted in two separate cases of sexually assaulting 10-year-old girls and was serving a long prison term in Delaware.

Detectives went to speak with him. He admitted that he left the mall with the Lyon sisters, according to court records, and detectives have conducted numerous interviews with him.

Authorities have said that Richard Welch remains a primary focus in the case. At least three relatives have implicated him, according to court records:

●Lloyd Lee Welch, who told detectives that the day after the Lyon sisters disappeared, he was at Richard Welch’s home and saw Richard Welch sexually assaulting one of the girls, according to court records. Lloyd Lee Welch has also told detectives that he saw his own father — also named Lloyd Lee Welch — and Richard Welch kill one of the Lyon sisters, court records state.

●A nephew of Richard Welch’s, Thomas Welch Jr., said that on Easter Sunday, five days after the Lyon sisters were at the mall, he saw two young blond girls at his uncle Richard Welch’s home. He told detectives that he thinks the girls were the Lyon sisters, according to court records.

●A second nephew of Richard Welch’s, who lives in Calvert County, has told detectives that within the past year, Richard Welch told him that in 1975, he and other family members raped and killed the Lyon sisters and disposed of their bodies in Bedford County, according to court records.