Kemp, 63, was given a lethal injection at the state prison in Florence for the 1992 murder of a college student whose body was dumped at a desert ghost town.
The Arizona Republic said Kemp washed down his final meal with root beer and told the assembled witnesses, "I regret nothing." Kemp then appeared to tremble as the fatal combination of drugs took effect and died quietly.
The execution was the third in Arizona this year and closed the books on a crime spree that took Kemp and an accomplice from Arizona to Colorado.
The Republic said Kemp was a maintenance man at a Tucson trailer park when he connected with Jeffrey Logan, a California prison escapee, and set out to commit a robbery.
The pair abducted 25-year-old college student Hector Juarez from an apartment complex parking lot. After forcing Juarez to take out cash from an ATM, he was shot in the head and dumped near the Silverbell Mine northwest of Tucson.
Kemp and Logan drove Juarez's truck to Flagstaff where they sold the vehicle and then carjacked a couple and forced them to drive them to Colorado.
Logan was later arrested in Denver and Kemp was tracked down at a Tucson homeless shelter.