Fromme was born in 1948 in Santa Monica, the daughter of an aeronautical engineer. As a child, she danced with a touring group called the Westchester Lariats, performing on The Lawrence Welk Show and at the White House. The trajectory was wholesome, even charmed. But after the family moved to Redondo Beach, Fromme began using alcohol and drugs, and her grades collapsed at Redondo Union High School. She graduated in 1966 and briefly enrolled at El Camino College before her father kicked her out following an argument. Homeless at nineteen, she drifted to Venice Beach, where she met a recently released federal prisoner named Charles Manson. She became the second member of what would grow into the Manson Family.

Fromme lived with the Family at Spahn Ranch, an aging movie set in the hills above the San Fernando Valley, and later at the remote Barker Ranch in Death Valley. She found purpose in Manson's apocalyptic philosophy and traveled with a shifting group that included Mary Brunner and Susan Atkins. When Manson and three followers were arrested for the 1969 murders of Sharon Tate and Leno and Rosemary LaBianca, Fromme was not charged -- she had not participated in the killings. Instead, she and the remaining Family members camped on the sidewalk outside the Los Angeles courthouse during the trial, carving X marks into their foreheads to match the defendants inside. She was convicted of attempting to prevent Manson's followers from testifying and of contempt of court, serving short jail sentences for both. Around 1973 she began writing a 600-page manuscript about the Family, but abandoned plans to publish it after concluding the material was too incriminating. The book, titled Reflexion, was eventually published in 2018.

On that September morning in 1975, Fromme positioned herself among the crowd in Capitol Park as Ford walked toward the California State Capitol. She drew the Colt M1911 and raised it. Secret Service agent Larry Buendorf seized her immediately. "It didn't go off. Can you believe it? It didn't go off," she said as she was brought to the ground. At trial, she refused to cooperate with her own defense. "I was not determined to kill the guy," she claimed, but the jury convicted her of attempted assassination under a 1965 federal statute. When the U.S. Attorney recommended severe punishment, calling her "full of hate and violence," Fromme threw an apple at his face, knocking off his glasses. She told the press she had "came to get life. Not just my life but clean air, healthy water, and respect for creatures and creation." The sentence was life imprisonment. Remarkably, just seventeen days after Fromme's attempt, another woman -- Sara Jane Moore -- tried to shoot Ford in San Francisco, making him the target of two assassination attempts in the same state within three weeks.

Prison did not quiet her. In 1979 she attacked a fellow inmate with a hammer and was transferred from the Dublin federal facility in California. On Christmas Eve 1987, she escaped from Federal Prison Camp Alderson in West Virginia, attempting to reach Manson. She was recaptured two days later. The escape added years to her sentence. Fromme first became eligible for parole in 2005 but waived her right to a hearing. She was finally released on August 14, 2009, after approximately thirty-four years of incarceration. She moved to Marcy, New York, where she settled quietly with a companion. In a 2019 interview, she was asked whether she had been in love with Charles Manson. "Yeah," she said. "I still am." The spot in Capitol Park where she raised the pistol is unremarkable now -- just grass and shade trees and people on their lunch breaks, with no marker to indicate that a woman in a red robe once tried to change American history there.