The 60-year-old Welch is serving time in DE until 2026 for sexually assaulting a 10-year-old girl, after which he will serve a 48-year sentence in the Lyon sisters case. Welch is accused of kidnapping the 10 and 12-year-old sisters from a Washington D.C. -area shopping mall, then burning their bodies in Bedford County.
However, it does bring a form of closure to the murders that have haunted the region for decades. Authorities say Welch was at the mall the day the girls vanished and was seen paying attention to them.
"Our parents were very protective [after the sisters went missing]. We began to rear our children differently", said Montgomery County State's Attorney John McCarthy.
The first-degree felony murder charges carry the possibility of a death sentence, but it wasn't known before the hearing if prosecutors had agreed not to pursue the death penalty in exchange for Welch's guilty pleas.
Police didn't release the drawing to the public because they were focused on another sketch based on descriptions from witnesses who said they saw the sisters talking to an older man who had a microphone and cassette recorder.
The 48-year sentence is part of a plea agreement that also calls for him to receive a 12-year concurrent prison term for two unrelated sexual assaults in northern Virginia.
Prosecutor Wes Nance said Welch's credibility is "open for questioning".
John and Mary Lyon Credit AP
Welch, now 60, did not speak during the hearing, except when asked to enter his plea.
The defendant's lawyer Tony Anderson said: "It's our hope that with this agreement. will in some way add some closure in a meaningful, meaningful way to the Lyon family and Mr. Welch".
In interviews with police beginning in 2013, Welch acknowledged he was at the mall that day and said he believed they'd been "abducted, raped and burned up", according to court documents.
Prosecutors are unsure who, if anyone else, was also involved in the killing - other suspects, which included members of Welch's family, either did not have enough evidence for a conviction or have since passed away.
Welch is already serving a long prison term in DE for sexually molesting a 10-year-old girl. Once he completes that sentence in 2026, he will begin serving his sentence in Virginia.
John Lyon and his wife Mary are the girls' parents, and they say they just want to go home after their long ordeal.
Although Welch is technically eligible for parole when he reaches his 80s, experts said the chances of it being granted are "very slim or none", ABC News reports.
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