JACKSON, Ga. – Georgia executed Troy Davis on Wednesday night for the murder of an off-duty police officer, a crime he denied committing right to the end as supporters around the world mourned and declared that an innocent man was put to death.

Defiant to the end, he told relatives of Mark MacPhail that his 1989 slaying was not his fault. “I did not have a gun,” he insisted.

“For those about to take my life,” he told prison officials, “may God have mercy on your souls. May God bless your souls.”

Davis was declared dead at 11:08. The lethal injection began about 15 minutes earlier, after the Supreme Court rejected an 11th-hour request for a stay.

The court did not comment on its order, which came about four hours after it received the request and more than three hours after the planned execution time.

Though Davis’ attorneys said seven of nine key witnesses against him disputed all or parts of their testimony, state and federal judges repeatedly ruled against granting him a new trial. As the court losses piled up Wednesday, his offer to take a polygraph test was rejected and the pardons board refused to give him one more hearing.

Davis’ supporters staged vigils in the U.S. and Europe, declaring “I Am Troy Davis” on signs, T-shirts and the Internet. Some tried increasingly frenzied measures, urging prison workers to stay home and even posting a judge’s phone number online, hoping people will press him to put a stop to the lethal injection. President Obama deflected calls to get involved.

“They say death row; we say hell no!” protesters shouted outside the Jackson prison where Davis was to be executed. In Washington, a crowd outside the Supreme Court yelled the same chant.

As many as 700 demonstrators gathered outside the prison as a few dozen riot police stood watch, but the crowd thinned as the night wore on and the outcome became clear.

The scene turned eerily quiet as word of the high court’s decision spread, with demonstrators hugging, crying, praying, holding candles and gathering around Davis’ family. Laura Moye of Amnesty International said the execution would be “the best argument for abolishing the death penalty.”

About 10 counterdemonstrators also were outside the prison, showing support for the death penalty and the family of Mark MacPhail, the man Davis was convicted of killing in 1989. MacPhail’s son and brother attended the execution.