Edward Charles Allaway was born in 1939, possibly in Royal Oak, Michigan, and spent most of his early life there. He had a history of mental illness, including a diagnosis of paranoid schizophrenia. Prior to the massacre, Allaway exhibited violent behavior, including an incident where he injured a co-worker at a Michigan plant. Shortly before the shooting, he had threatened his wife with a knife and raped her. Allaway harbored delusions that pornographers were forcing his wife to appear in movies, which contributed to their separation over Memorial Day weekend in 1976.

On July 12, 1976, Allaway, a custodian at California State University, Fullerton, entered the university's library armed with a .22 caliber semi-automatic rifle. He opened fire, killing seven individuals and injuring two others. The victims included library staff and patrons. After the shooting, Allaway fled to a nearby hotel where his estranged wife worked. He called the police, confessed to the shootings, and surrendered peacefully.

In 1977, Allaway was convicted of six counts of first-degree murder and one count of second-degree murder. However, during the sanity phase of the trial, he was found not guilty by reason of insanity. Five mental health professionals diagnosed him with paranoid schizophrenia. He was committed to the California state mental hospital system, initially at Atascadero State Hospital, then transferred to Patton State Hospital. In 2016, Allaway was moved to Napa State Hospital, a less secure facility, prompting protests from victims' families.

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