Throughout his childhood, Kohlhepp expressed anger toward his stepfather. At age 12 in 1982, with his mother and stepfather split because of marital troubles, Kohlhepp was sent to live with his biological father for the summer.
Kohlhepp had barely known his father, not having seen him in eight years. His mother said she believed her son's problems might be because he never knew his father.
After the summer, Kohlhepp returned to South Carolina and demanded his mother send him back to Arizona. He threatened to kill himself or her if not allowed to go back.
The following school year, Kohlhepp was allowed to live with his biological father and even took the name Todd Sampsell. Kohlhepp worked as a dishwasher and busboy at his father's restaurant — Billy's Famous For Ribs — and did some landscaping and worked at a Burger King.
The relationship started out well, but deteriorated as Kohlhepp claimed that his father was always absent with any number of girlfriends.
During psychological evaluations, Kohlhepp indicated that his favorite hobby was collecting weapons, a trait he said he shared with his father who claimed to be a special forces soldier, mercenary and arms dealer who taught him how to "blow things up and make bombs." Attempts to reach his father by a USA Today Network newspaper in Arizona were unsuccessful.