Born in 1945, Costa was an infant when his father died in World War II. Around the age of seven, Costa told his mother that "a man" was entering his room by night, and he identified a photo of his father as the silent prowler. In November 1961, at age sixteen, he invaded a Somerville, Massachusetts, apartment, bending over the bed of a teenage girl before she woke and her screams drove him off. Three days later, he returned and tried to drag her down the stairs of her apartment house, but neighbors intervened. Convicted of burglary and assault on January 4, 1962, he drew a one-year suspended sentence, with three years probation. Costa was married in April 1963, fathering three children before drugs complicated the relationship, producing bizarre and irresponsible behavior. In June 1966, he brought home two hippie girls -- Bonnie Williams and Diane Federoff -- with the announcement that he would be driving them to Pennsylvania, moving on alone from there to California. Later, Costa told police he drove the girls to Hayward, California, but they never got there. Costa surfaced at his home in Massachusetts, ten days later, and the girls are now believed to be his first known victims . In August 1967, hiking in the Truro woods, near Provincetown, Costa shot a female acquaintance with an arrow, afterward apologizing for the "accident." By early 1968 his marriage was in shambles, and he drove to California in the latter days of January, settling briefly in San Francisco's free-swinging Haight-Ashbury district. Girlfriend Barbara Spaulding left her child with relatives and vanished on the day that Costa left for Massachusetts. She was never seen again, and homicide detectives now believe that Costa murdered her, as well. Back home in Massachusetts, Costa burglarized a doctor's office on May 17, stealing various surgical instruments and drugs valued at $5,000. A week later, 18-year-old Sydney Monzon vanished from her home in Provincetown; her disappearance was reported to police on June 14. By August, Costa was divorced; his brand-new live-in lover, Susan Perry, lasted for a week before she disappeared, September 10. When questioned, Costa told his friends that she had "gone to Mexico." In mid-September, Costa was arrested for driving with a suspended driver's license. Later, on the twenty-fifth, he was picked up for failure to support his wife and children, held in custody until November 8. Upon release, he started spending time and sharing drugs with Christine Gallant, another habitue of the "hip" scene. On the weekend of November 23, Gallant was found dead in her New York apartment, drowned in the bathtub after a barbiturate overdose. On January 24, 1969, Patricia Walsh and Mary Anne Wysocki disappeared on a visit to Provincetown. Two weeks later, searchers found a woman's mutilated body at the Old Truro cemetery, identified as the last remains of Susan Perry. On March 4, the dismembered bodies of Walsh, Wysocki, and Sydney Monzon were found buried together, a mile and a half from the first grave site. Walsh and Wysocki had both been shot in the head, with hearts removed from all three victims; the remains bore human teeth marks, and the coroner discovered evidence of necrophilia . Investigators learned that Walsh and Wysocki had met Antone Costa in Provincetown. Found in possession of their car, Costa produced a suspicious bill of sale, claiming he purchased the vehicle before the women "left for Canada." He was arrested on suspicion of murder after detectives learned that the burial site was Costa's private "garden," used for stashing drugs and growing marijuana. In custody, the suspect changed his story several times, twice implicating innocent friends in the murders, repeatedly failing polygraph examinations. His first psychiatric exam, on March 31, resulted in the diagnosis of a "schizoid personality." Three months later, a second psychiatrist characterized Costa as "a modern-day 'Marquis de Sade' " and a "sexually dangerous man," capable of murder. The floodgates opened on July 12, 1969, when Costa finally confessed to the murder of Mary Wysocki. Costa's trial opened on May 6, 1970, ending with his conviction on four counts of murder. Sentenced to life imprisonment on May 29, he began stocking his cell with books on ritual magic and the occult , including a copy of Anton LaVey's Satanic Bible. Four years later, on May 12, 1974, Costa was found hanging in his prison cell, a leather belt around his neck. The death was held to be a suicide.