Last week, Arapahoe County, Colo., District Judge William Sylvester set the week of Aug. 18 as Dunlap's execution date.
In 1993 Dunlap, then 19, went to the Chuck E. Cheese restaurant where he once worked and killed employees Ben Grant, 17, Colleen O'Connor, 17, Sylvia Crowell, 19, and Margaret Kohlberg, 50, and shot and injured Bobby Stephens, in a robbery attempt, The Denver Post said Tuesday.
Dunlap is now Colorado's longest-serving death-row inmate.
The 25-page petition asks for clemency, and a reduction of Dunlap's death sentence to life imprisonment without parole. Also filed with the petition were letters from his supporters and from death penalty opponents, a videotape explaining the violence and sexual abuse inflicted on him as a child and a hand-written letter by Dunlap acknowledging his crime, the newspaper said.
Although Dunlap's lawyers and the governor's office have expressed uncertainty over whether a response is required, Hickenlooper's spokesman, Eric Brown, said, "I think at some point he (Hickenlooper) will have to make a response."