The execution remained on hold under a stay granted earlier in the week because the state attorney general's office did not file an appeal Friday, The Atlanta Journal-Constitution reported.
Attorney general's office spokeswoman Lauren Kane said prosecutors need a transcript of this week's hearings before Fulton County Superior Court Judge Gail Tusan before an appeal could be filed. She said the transcript will not be ready until Monday, the Journal-Constitution said.
"We are deeply relieved that Warren Hill will not be executed tonight in order for the courts to more thoughtfully deliberate Mr. Hill's mental retardation claim and the extreme secrecy surrounding Georgia's lethal injection law," defense attorney Brian Kammer said.
Kammer contends Hill should not be executed because he is mentally retarded, but the stay was granted to consider the constitutional concerns about a new state law that keeps secret the identities of those who make and supply Georgia's lethal injection drugs.
The delays also mean the warrant ordering Hill's execution will expire at noon Saturday and state attorneys will have to go back to a judge to get a new warrant that provides a one-week window to carry out the execution.
Another impending complication is the state's aging supply of pentobarbital, the drug it needs to carry out Hill's execution. Court records indicate its current supply expires Aug. 8.
Hill was sentenced to life for killing his 18-year-old girlfriend. In 1990, he fatally battered fellow inmate Joseph Handspike, drawing the death penalty.
Biologists detail four new deep-sea 'killer sponges'
Pistorius testifies he didn't consciously pull trigger when he shot girlfriend