Robert Carl Hohenberger was born in Indiana in 1943 and later moved to Riverside County, California. In the mid-1960s, he served as an auxiliary deputy sheriff but began committing heinous sexual crimes against women and girls—initially assault, followed by rape at gunpoint. Convicted in 1966, he received a reduced sentence after a plea deal and relocated to Orange County upon release.

In 1971, he was arrested for kidnapping two teenage girls and sentenced to life in prison with parole eligibility after six months. Imprisoned at San Quentin, he later escaped on April 12, 1974. Despite being recaptured within hours, he served his escape sentence and was paroled in August 1977.

After parole, Hohenberger slipped back into criminal behavior. In October 1977, he abducted and raped a young woman in Palm Desert. Identified through mug shots, he fled California in January 1978, eventually arriving in Morgan City, Louisiana, operating under the alias Frank Henry Green.

Between March and May 1978, a trio of teenage disappearances in Morgan City drew FBI involvement. Hohenberger, then settled in the area, was suspected after victims ranging from 15 to 19 were abducted, sexually assaulted, and found murdered. The first victim, Mary Leah Rodermund, vanished on March 2; she and others like Bridget Cantrell Sons, Gordon Cannella, and Judy Adams were confirmed to have been killed.

Search efforts uncovered the bodies—two girls in a septic tank, then a teenaged boy nearby—prompting a federal murder warrant. As authorities closed in on Tacoma, Washington (where he attempted to sell a stolen car), Hohenberger was found in a hostage situation during an attempted arrest. He shot himself and died several hours later on May 31, 1978, avoiding trial and conviction.