A jury convicted him of first-degree murder and conspiracy to commit first-degree murder for the death of Pediatric Ophthalmologist Brian Stidham.
Bigger is serving concurrent prison terms of natural life.
Detectives with the Pima County Sheriff's Department solved the murder-for-hire plot when they were first called to a body found in the parking lot of a medical plaza on Oct. 5, 2004, in Tucson.
Detectives say Stidham's former business partner Bradley Schwartz hired Bigger to kill Stidham.
Schwartz is serving life for conspiracy to commit first-degree murder. He has a chance at parole after 25 years.