Marlin Gray, convicted of two counts of first-degree murder in the killings of two sisters in April 1991, was executed early Wednesday after Missouri's governor rejected appeals for clemency by a black US congressman and Amnesty International. Gray, who maintained his innocence to the end, was the fifth person put to death in Missouri this year. Gray lifted his head off a gurney just before the first of three drugs was injected into his body and mouthed words to his witnesses, a cousin and her minister, then fell silent. He previously had said he didn't want any family members or friends to witness the execution. He was pronounced dead at 12:07 a.m. Wednesday at the Eastern Reception Diagnostic and Correctional Center in Bonne Terre. Gray, 38, was convicted in 1992 in the deaths of sisters Julie and Robin Kerry on an abandoned Mississippi River bridge in St. Louis on April 4, 1991.