[7] Furthermore, prosecutors have named other members of Welch's family – including his uncle[8] – as persons of interest in the girls' abduction, abuse and murder, although no other individuals have been charged due to insufficient evidence.

[21] By 5:45, Mary Lyon had begun preparing the family's evening meal of fried chicken; she later recollected feeling slightly annoyed her daughters had not returned home by this time.

[25] Suspecting a likely sexual motive behind the sisters' abduction, several known pedophiles and sex offenders were questioned in the weeks following their disappearance; all were eliminated from the inquiry upon verification of their alibis.

[29] Both the family and police received numerous calls from hoax callers, attention-seekers and extortionists claiming to be holding the girls for ransom in the immediate aftermath of their disappearance.

One of these calls was received from an anonymous male caller on April 4, 1975; this individual demanded that John Lyon leave a briefcase with $10,000 (the equivalent of about $58,600 as of 2025[update])[30] inside an Annapolis courthouse restroom.

The man had been approximately six feet in height, well-groomed, conservatively dressed, aged between 50 and 60 and wearing a brown suit[17] and was carrying a briefcase with a tape recorder inside.

According to this witness, both the Lyon sisters and other children present spoke into a microphone the man was holding, believing their voices were to be broadcast live upon a local radio station.

[21] A police sketch artist also created a composite drawing based on this eyewitness's description; this depicted a white male in his late teens or early 20s, approximately 5 feet 11 inches (1.80 m), with notable acne on his face, scars on his left cheek, somewhat shabbily dressed, and wearing a light-colored Peters Jacket.

Aside from the major differences in facial features, hair and clothing, the young male leering at the sisters and the middle-aged man encouraging children to speak into his microphone were several decades apart in age.

This timeline of the children's movements prior to their disappearance was released to the public:[35] On the day following the first media circulation of the composite drawing of the middle-aged man carrying a briefcase with a tape recorder – April 1, 1975[25] – an 18-year-old Appalachia native named Lloyd Lee Welch Jr. traveled to the shopping center to specifically inform a security guard he had seen a man matching the police description of the suspect at the premises on March 25.

[8] On April 6, an 11-year-old boy named William Krebs reported he had seen the sisters inside a white two-door Pontiac sedan driving along U.S. Route 211 in Centreville, Virginia, shortly after they are believed to have been abducted.

[40] Other contemporary press reports indicate that a man matching the sketch of the middle-aged individual at the shopping center had actually been seen a few weeks prior to the Lyon sisters' disappearance approaching several young girls and asking them to recite an answering machine message typed on an index card into his hand-held microphone.

Although the media devoted considerable attention to the sisters' disappearance and press interest in the case remained intense for several weeks, no conclusive leads as to the girls' whereabouts emerged.

[21] On May 23, 1975, Maryland Lieutenant Governor Blair Lee ordered 122 National Guardsmen to participate in a search of a Montgomery County forest for the missing girls – again to no avail.

Although Coffey was younger than the middle-aged individual described by eyewitnesses as initiating conversation with the Lyon sisters and others via his tape recorder, the method of ensnaring children via this modus operandi piqued investigators' interest.

[25] Critically, Homrock noticed a mug shot taken of Welch in 1977 pertaining to a burglary closely matched the 1975 composite drawing of the young Caucasian man whom witnesses stated had leered at the Lyon girls within the Wheaton Plaza shopping center shortly before their abduction.

"[25] In response, Detective David Davis placed a photograph of the Lyon sisters before Welch, stating: "These two little girls here have never been found, and their parents are damn near eighty years old and have no idea what happened to their daughters; that's why we're here to talk to you.

"[46] In this initial interview, Welch acknowledged observing the sisters near the shopping center on the date of their disappearance, although he denied being present within the premises; he then expanded his admission to claim to have seen "a guy putting two girls in the back of a car.

Shown a photograph of a known child sex trafficker named Raymond Mileski Sr., whom investigators had previously considered a strong suspect, Welch insisted he was the individual he had seen abducting the Lyon sisters.

[11] Contemporary eyewitness accounts of the individual with the tape recorder in the Wheaton Plaza shopping center and considered a likely suspect in the Lyon sisters' abduction indicated the man walked with a slight limp – as had Mileski.

[48] In subsequent interviews with investigators, Welch denied Mileski's culpability in the sisters' abduction and murder; he also contradicted several other claims given in his initial interrogation in the twelve subsequent interviews granted to investigators – alternating between instances of denial of involvement in the sisters' kidnapping and murder, knowledge of relatives' culpability in the crime while maintaining his own innocence, and limiting his participation to the planning and commission of the kidnapping.

Investigators revealed Welch, who was eighteen years old in 1975, was an Appalachian native with a violent temper whose family lived insular lifestyles and frequently engaged in incest – both consensual and unconsensual.

[55] This basement was accessible solely via a single padlocked door at the rear of the property and according to Welch, his father and uncle had threatened him, prompting him to simply leave the children at their mercy at this location.

[60][61] The sole physical evidence recovered consisted of several small degraded bone fragments of human origin,[62] a single human tooth, a section of charred wire (potentially originating from Sheila's wire-rimmed glasses), and remnants of a beaded necklace or bracelet similar to one habitually worn by Katherine – all recovered from the precise location of the 1975 fire neighbors of the Welch family recollected.

[67][68] According to Parker, he had helped remove two army-style duffel bags from Welch's vehicle; each covered in red stains, weighing "about 60 or 70 pounds and [smelling] like death".

[8] None of these neighbors had suspected any form of foul play or criminal activity surrounding the fire as the act of residents "burning trash" at this location was commonplace.

[54] At a press conference held to announce this development, Bedford County Sheriff Michael Brown informed reporters the Lyon sisters had been sexually abused, then "killed in order for their captors to escape detection.

[57] By the time of Welch's indictment, cold case investigators had devoted over 16,000 hours to the re-investigation of the sisters' disappearance, had issued over fifty search warrants, and conducted over one hundred formal interviews with family members, eyewitnesses, and other persons of interest.

[38] As per statutory requirements, upon Welch's completion of his prison term in Delaware in 2026, he will be transferred to Virginia to begin serving his formal sentence for his convictions in this state.

[50][73] Following Welch's conviction, John Lyon thanked cold case detectives and law enforcement officers on behalf of his family for never ceasing in their efforts to bring those responsible for his daughters' abduction and murder to justice, stating: "We just want to say, 'Thank you'.