Edmund Emil Kemper III was born on December 18, 1948, in Burbank, California, into a troubled family environment12. His childhood was marked by a tumultuous relationship with his alcoholic mother, Clarnell, who was reportedly abusive and critical1. From an early age, Kemper exhibited disturbing behavior, including cruelty to animals. At 10, he buried a pet cat alive and later decapitated it, and at 13, he killed another family cat2. He also engaged in macabre games with his sisters, such as "electric chair" and "gas chamber"3. Despite his troubled upbringing, Kemper demonstrated high intelligence, with tests revealing an IQ of 1454. This combination of a difficult home life, early signs of violence, and high intelligence would later play a significant role in his development as a serial killer.

At the age of 15, Edmund Kemper committed his first murders, killing his paternal grandparents on August 27, 1964. He shot his grandmother, Maude Matilda Kemper, after an argument, and then killed his grandfather, Edmund Emil Kemper Sr., upon his return from grocery shopping.1 Kemper later claimed he "just wanted to see what it felt like to kill Grandma" and killed his grandfather to spare him from discovering his wife's death.1 Following his arrest, Kemper was diagnosed with paranoid schizophrenia and sent to Atascadero State Hospital, a maximum-security facility for mentally ill convicts.1 Despite concerns from psychiatrists and Kemper himself, he was released at age 21 in 1969, after just five years of confinement.3

Between May 1972 and February 1973, Edmund Kemper embarked on a horrific killing spree in the Santa Cruz area, murdering six young women and earning the moniker "Co-ed Killer." Kemper targeted female hitchhikers, using his large stature and seemingly gentle demeanor to lure victims into his vehicle13. After killing the women, Kemper would often take their bodies to his apartment where he engaged in necrophilia and dismemberment3. He decapitated his victims, sometimes burying their heads in his backyard or keeping body parts as trophies4. Kemper's victims included college students Mary Ann Pesce, Anita Luchessa, Cindy Schall, Rosalind Thorpe, and Alice Liu, as well as 15-year-old Aiko Koo34. His high intelligence allowed him to evade capture, even passing through a police checkpoint with bodies in his trunk3. Kemper's reign of terror, along with other active serial killers in the area, led to Santa Cruz being dubbed the "Murder Capital of the World" by the press4.

In April 1973, Edmund Kemper committed his final murders, killing his mother Clarnell Strandberg and her friend Sally Hallett. On Good Friday, Kemper bludgeoned his sleeping mother with a hammer, slit her throat, and decapitated her24. He then called Hallett to the house and strangled her2. After these murders, Kemper fled to Colorado, where he called the Santa Cruz police on April 23 to confess his crimes3. Initially skeptical, the police eventually took him into custody after multiple calls5. Kemper later explained that he felt he could no longer handle the emotional toll of his crimes and decided to turn himself in3.