Gregory Paul Lawler, 63, has been executed for murdering an Atlanta police officer 19 years ago.

Lawler was pronounced dead at 11:49 p.m. Wednesday at the Georgia Diagnostic and Classification Prison near Jackson, where the state’s death chamber is located.

The United States Supreme Court denied a stay of execution shortly after 11 p.m., clearing the way for Lawler to get a needle filled with a fatal dose of the sedative pentobarbital.

The lethal injection had been slated for 7 p.m., but executions are routinely delayed by last-gasp legal appeals. The Georgia Supreme Court announced Wednesday evening that it had denied late defense requests to halt the execution. And the state Board of Pardons and Paroles rejected a clemency request Tuesday that focused on Lawler's recently diagnosed autism.

Lawler was convicted of murdering John "Rick" Sowa, a 28-year-old Atlanta policeman, and wounding Sowa's partner, Pat Cocciolone, on Oct. 12, 1997, just moments after the two officers walked Lawler's intoxicated girlfriend to the front door of the apartment they shared.

Sowa and Cocciolone were sent to investigate a report of a man hitting a woman behind a business near the intersection of Lindbergh Drive and Piedmont Avenue. They found Lawler trying to pull his girlfriend, Donna Rodgers, who was drunk, to her feet. After Lawler walked away, Sowa and Cocciolone drove Rodgers home.

Lawler greeted the officers at the door with obscenities and told them to leave. When Sowa tried to stop Lawler from closing the door, Lawler grabbed an AR-15 loaded with armor-piercing bullets and fired at the fleeing officers.

Sowa was shot dead a few feet away. Cocciolone, gravely wounded, managed to call for help.

Both were wearing bullet-proof vests. Their guns were still holstered.

Lawler spent much of the day Wednesday visiting his brother, Gerald, at the prison. At 3 p.m. he was given a physical and was then served his last meal — a rib-eye steak, a baked potato with sour cream, asparagus, dinner rolls with butter, French onion soup, strawberries, pistachio ice cream and apple juice. Prison officials said he ate all of it.

Lawler's lethal injection is the state's seventh in 2016, the most executions Georgia has carried out in a year since the death penalty was reinstated nationwide in 1976. Texas is the only other state that has carried out as many as seven executions since Jan. 1.

— The Associated Press contributed to this article.