Born in 1948 at Toledo, Ohio, and raised in rural, Fayette County, Davis dropped out of high school in the mid-1960s and moved to Manhattan, in hopes of pursuing a singing career. He earned a diploma from night school, in 1968, but success in show business eluded him, leaving the young man embittered, struggling to make ends meet. A sexual assault at age thirteen left Davis hating homosexuals, and when his cash ran short he hatched a plan to prey upon his childhood enemies, seducing gays and robbing them of cash and other valuables.
In February 1972, Davis was arrested in Washington, D.C., and charged with the murder of a local businessman, James Earl Hammer. Convicted of manslaughter, he drew a sentence of five to fifteen years imprisonment before Illinois authorities linked him with the strangulation of Rev. Carlo Barlassina, murdered in a Chicago hotel on June 29, 1971. Extradited to Chicago in December 1972, Davis was convicted of murder, his 25-to-45-year prison term consecutive with his existing sentence.
Serving his federal time first, Davis logged eight and a half years in the lockup at Terre Haute, Indiana, with side trips to the prison hospital at Springfield, Missouri. In 1979, he was transferred to the Illinois state prison at Menard, where he remained until October 1982. On the afternoon of October 24, Davis armed himself with an ax, fatally wounding Joe Cushman, a guard, before fleeing in Cushman's car. The vehicle was recovered next day, near Christopher, Illinois, but Davis remained at large until Halloween, when deputies picked him up for attempted auto theft in Smithers, West Virginia.
Back in custody, the homicidal drifter launched into rambling confessions, claiming 32 murders between 1969 and 1971. With a few exceptions, his victims were described as wealthy professional men, seduced with promises of sex, then killed for profit and amusement. The body-count included eight victims in Washington, D.C. and more in the suburbs, five in New York, with others in Baltimore, Boston, Fort Lauderdale, Reno, Las Vegas, New Orleans, Los Angeles, and San Juan, Puerto Rico.
Authorities in Illinois confirmed at least four slayings, based on Davis's intimate knowledge of the crime scenes, and New York police "feel certain" of his guilt in the May 1970 strangulation of voice teacher Eric Tcherkezian. Returned to Illinois in mid-November 1982, Davis was convicted of Joe Cushman's murder ten months later and sentenced to life.