Police have charged a suspect with murder in a 40-year-old cold case involving the disappearance of two young sisters whose bodies were never found. Lloyd Welch—an imprisoned sex offender—was identified as a person of interest after investigators noticed that his 1977 mugshot resembled a sketch of the original suspect, and indicted after 10 months of secret grand-jury proceedings. If the case goes to trial, it would be the longest gap between an alleged crime and a “no-body” trial in U.S. history. Sheila Lyon, 12, and sister Katherine, 10, disappeared from a Maryland mall in 1975. Welch, 58, is serving time for burglary and sexual assault and molestation of two 10-year-old girls.