Reign of terror: August 1965 - 1973
Motive: Revenge and sex
Crimes:
| Date | Victim | Method | Place |
| 27/08/65 | His grandmother | Shot in the head with a rifle and stabbed | North Fork, California |
| 27/08/65 | His grandfather | Shot with a rifle | North Fork, California |
| 07/05/72 | Mary Ann Pesce | Stabbed, and throat cut | Santa Cruz |
| 07/05/72 | Anita Luchessa | Stabbed | Santa Cruz |
| 14/09/72 | Aiko Koo | Suffocated | San Francisco |
| 09/01/73 | Cindy Schall | Shot | Santa Cruz |
| 05/02/73 | Rosalind Thorpe | Shot | Santa Cruz |
| 05/02/73 | Alice Liu | Shot | Santa Cruz |
| 21/04/73 | Clarnell Kemper, his mother | Hammer blows to the head | Santa Cruz |
| 21/04/73 | Sally Hallett | Strangulation | Santa Cruz |
Sentence: Seven consecutive life sentences.
Interesting facts: Kemper's problems started when he was a child. His family consisted of an alcoholic father, an overbearing mother, and two favoured sisters. At the age of ten, his parents divorced, and his mother and sisters moved him out of his bedroom and into the cellar. At school, despite his large size (he was 6 foot nine at the time of the murders, weighing 300 pounds) he was regarded as weak and cowardly. He killed two pet cats, burying the first one alive and cutting the second's head off with a machete, keeping the head for several days "worshipping" it. He also had a habit of cutting off the heads and hands of his sister's dolls.
When both his parents remarried, Kemper did not get on with either step-parent and at 15, went to live with his grandparents on their farm in the Sierra Mountains. This relationship was also rather stormy. His grandfather gave him a rifle and encouraged him to shoot rabbits and gophers. However, instead, when his grandmother admonished him, he shot her in the head twice. When his grandfather returned home, he shot him too before he got to the house, so that he didn't find his wife lying dead. When apprehended by the police, he said "I just wondered how it would feel to shoot Grandma". These murders earnt him a spell in the California State Hospital at Atascadero.
The hospital at Atascadero specialised in treating sex offenders, not caring for disturbed 15-year-old boys. During his stay there, Kemper learnt about many aspects of sex and violence, and that most rapists are caught because their victims identify them. He also learnt an amount of psychology, from the many psychologists that examined him. After five years, he passed all the tests that showed he was rehabilitated and was released in 1969. Following a short time in a half-way house, against the advice of the state psychiatrists, he returned to live with his mother, the woman who even Kemper himself identified as being the source of his problems. For the next two years, Kemper cruised the streets giving hitch-hikers a lift, teaching himself the best way to pick up hitch-hikers without being conspicuous, perfecting his manner so that they wouldn't be alarmed by his manner, and spending time in a local bar frequented by police officers. He even applied to join the police force, but was rejected, apparently due to his large size.
The majority of Kemper's victims were hitch-hikers from the large student community in Santa Cruz. He would drive around looking for a suitable target. Once in the car, he would take them to a secluded area off the freeway, and kill them. He then put them in the boot of his car. He decapitated all of them. Some he took back to his home and sexually assaulted their corpses, before disposing of their bodies in a variety of places. In September 1972, the authorities sealed Kemper's juvenile record, as they were pleased with his progress - the decapitated head of Koo was in the boot of his car at the time. With his juvenile record sealed, he was able to buy a gun, which made it easier to dispatch his victims.
By Easter 1973, the bodies of his victims were beginning to be found, and linked to each other. The investigation was being hampered by the works of two other serial killers working in the same area at that time - Herbert Mullin and Linley Frazier. Kemper realised that he would soon be caught, and fantasised about going on a final killing spree. However, instead he chose to kill his mother. He then phoned up one of his mother's friends and invited her over for a meal, but killed her on her arrival. He then drove away to no particular destination. When he reached Colorado two days later, he phoned the police and gave himself up.
When he was arrested, Kemper confessed to everything he had done, including the detailed ways in which he had decapitated and dismembered the bodies. He also told the police how he had sliced meat off the legs of two of his victims and eaten them in a casserole. He also showed them exactly where he had disposed of all the bodies which had not yet been discovered. His defence of insanity was rejected by the jury at his trial and he was found guilty. As there was no death penalty in California at the time, he was sentenced to life imprisonment.