A Vermont native and member of the fundamentalist Christadelphian Church, Schaefer first ran afoul of authority while serving in the Navy. Charged with arson and possession of illegal drugs, he responded with an insanity plea, but the Navy psychiatrists found him competent for trial. On discharge, he succeeded in convincing friends and relatives of his normality, but violent sexual obsessions simmered just below the surface of his quiet personality, the pressure mounting toward a detonation point.

In 1979, Schaefer kidnapped, raped and murdered 13-year-old Sherry Nastasia, whose family lived in a Springfield apartment complex managed by Schaefer's brother. Theresa Fenton suffered an identical fate in 1981, but 17-year-old Deana Buxton survived an attack in Brattleboro, during 1982. Her description focused police attention on Schaefer, but hard evidence was still lacking in early 1983, when the killer struck again.

On April 9 of that year, Schaefer abducted young Catherine Richards in Springfield, driving her to a remote location where she was forced to fellate him before he crushed her skull with a stone. The body was discovered at noon on April 10, and eyewitness descriptions of Catherine's abductor matched those of Deana Buxton's assailant the previous year. Police were working their way up to an arrest in September 1983, when the last victim's mother penned an open letter to Schaefer, accusing him of murder and challenging him to confess his sins, in accordance with the precepts of his church.

It was the final straw, and Schaefer cracked in custody, confessing on two counts of murder (Fenton and Richards), plus the rape of Deana Buxton. In December 1983, he pled guilty to kidnapping, sexual assault, and second-degree murder in the Richards case, with charges dismissed in the Fenton murder as part of a plea bargain. A month later, Schaefer was sentenced to a term of 30 years to life, his time to be served at the federal penitentiary in Leavenworth, Kansas.