He spoke to a San Diego T.V. station and admitted he knew exactly what he was doing.
"I was aware of what I was doing and I could not stop myself. I was pent up with major rage and pissed off at my whole life and everybody that's hurt me. I blew up and hurt the wrong people."
The bodies of Chelsea King and Amber Dubois were found in nearby parks in February and March.
Gardner says he hates himself for committing the crimes and would take it all back if he could. He also offered to talk to both victims' families about the crimes.
Amber's mother says she plans on meeting with Gardner in private.