In January 1983 a Morris County man with stab wounds told police a woman had attacked him while he was driving alone at night. The detectives who questioned him, as a routine, noticed that his car matched the description eyewitnesses had given of the car used to abduct an eighteen-year-old in November, and that its tire treads matched tracks left by the killer. They looked at his wounds, and found he had inflicted them himself. He said he had only been driving around the area where Amie Hoffman was taken on the night she died. The next day police named James Jerold Koedatich as a suspect, searched his car under a warrant, and found clothing fibers from Amie Hoffman and from a second murdered woman, Deirdre O'Brien.
Koedatich was born in Morristown, New Jersey, on June 12, 1948, one of four sons of Julia and John Koedatich. His father was said to beat, kick and slap his wife, and in 1956, after she was hospitalized, he left the family for another woman; Julia raised the boys alone, working three jobs. At nineteen, in 1967, James was sentenced to a year in prison for unlawful use of a dangerous weapon, and after more arrests for petty crimes he moved to Florida in 1971.
There he shared an apartment in Surfside with a forty-year-old man, Robert J. Anderson. On June 7, 1971, he was arrested for armed robbery, and while awaiting trial he escaped from the county jail. On June 13 he strangled Anderson and hid the body in a closet. He was caught, convicted of second-degree murder, and served eleven years at the Florida State Prison in Raiford. On September 4, 1973, he stabbed to death a fellow inmate, Jerry Kent Barber, who was serving twelve years for kidnapping; the killing was ruled self-defense and he was not charged. In 1982 the Florida Parole Board released him, and that August he went home to Morristown.
On November 23, 1982, Amie Hoffman, a cheerleader at Parsippany Hills High School, was leaving her job at a mall in Hanover Township when he seized her and threw her into his car. He drove somewhere secluded, sexually assaulted her, stabbed her to death, and put her body in the Mendham Reservoir in Randolph Township. The moving water carried it into a holding tank, where it was found two days later. The autopsy recovered her killer's semen. On December 5 he ran twenty-five-year-old Deirdre O'Brien off the road, took her at knifepoint to an Interstate 80 rest area, raped her and stabbed her repeatedly, and left. A truck driver found her alive at the roadside, and she died in the hospital.
He was tried separately for the two murders and convicted in both, while insisting he was innocent, and was sentenced to death and sent to New Jersey's death row. In 1990 the Supreme Court of New Jersey overturned the death sentence and he was resentenced to life in prison. In 2011 he asked the Department of Corrections to move him to a prison in Illinois to be nearer his family; Commissioner Gary Lanigan refused. In 2017 he contacted the Innocence Project asking for newly discovered DNA evidence to be analyzed in the hope of clearing his name. His parole date is set for 2038, when he will be about ninety.