ATLANTA -- A Georgia man sentenced to death for the execution of a police officer is scheduled to be put to death on Oct. 27.

The Supreme Court on Tuesday cleared the way for Troy Davis to be put to death, despite calls from his supporters to reconsider the case because seven of nine key witnesses against him have recanted their testimony.

Davis, 40, was sentenced to death for the 1989 murder of 27-year-old Savannah police officer Mark MacPhail.

But doubts about his guilt and a high-profile publicity campaign have won him the support of prominent advocates including former President Jimmy Carter and South Africa Archbishop Desmond Tutu.