Between May 1972 and April 1973, Kemper embarked on a murder spree that started with two college students and ended with the murders of his mother and her best friend. He would pick up female students who were hitchhiking and take them to isolated areas where he would shoot, stab, smother or strangle them. He would then take their lifeless bodies back to his home where he would perform irrumatio on their severed heads, have sex with their corpses, and then dissect and dismember them.
During this 11-month spree, he killed five female college students, one high school student, his mother and his mother's best friend. Kemper has stated in interviews that he would often go hunting for victims after his mother's outbursts towards him, and that she would not introduce him to women attending the university where she worked. He recalled: "She would say, 'You're just like your father. You don't deserve to get to know them'." Psychiatrists, and Kemper himself, have espoused the belief that the young women were surrogates for his ultimate target, his mother, and that the humiliating acts he committed with his mother's corpse support this hypothesis.