On November 4, 1987, nine-year-old Frankie Barnes was reported missing when he failed to return from a neighborhood bike ride in Providence, Rhode Island. His bicycle was found two weeks later, concealed in tall grass near an abandoned brewery, less than a half-mile from his home.

A month later, on December 14, six-year-old Jason Wolf vanished in Providence, after his mother sent him out to retrieve the daily mail. Teenagers found his body on December 21, two miles from home, discarded in some brush near Mashapaug Pond. An autopsy revealed the cause of death as blows to the head, inflicted with a blunt instrument. Police were still puzzling over the case five days later, when they received an anonymous note in the mail. It read:

You will find the little boy by a wooden cross near Tongue Pond. I didn't want to do it. Satan ordered me to. I hope you will kill me, cops, because I don't know why I killed the children.

Following the note's instructions, searchers found Frankie Barnes on the northern shoreline of Tongue Pond, his body gashed by multiple stab wounds. An examination of the envelope revealed faint impressions of a man's name, followed by the phrase: "Catch me if you can, ha, ha, ha." Police called on the suspect, and he suggested his name might have been used by an enemy, William Sarmento, who had recently tried to seduce the man's girlfriend.

Police were familiar with the 21-year-old Sarmento. In 1985, he pled guilty to assaulting a neighborhood dog catcher and was sentenced to one year's probation. Three days later, he was picked up again, on charges of assault with a dangerous weapon, and he served 20 days in jail for violating his probation. Residents of Frankie Barnes's neighborhood recalled seeing Sarmento in the vicinity, and investigation disclosed that Sarmento was a childhood acquaintance of Jason Wolf's mother.

Detectives held a press conference on December 29, 1987, naming Sarmento as their primary suspect in two murders. Later that day, he was seen ducking into a cellar and police were summoned to make the arrest. Held without bond pending psychiatric evaluation, Sarmento is rumored to have confessed to both homicides.