Michael Yowell, 43, told witnesses at the Texas State Penitentiary in Huntsville, including his daughters and ex-wife, he loved them, then told the prison warden: "Punch the button." He took several deep breaths, then began snoring. Within 30 seconds, movement stopped and he was pronounced dead 19 minutes later.
He had comitted his crimes 15 years ago when he shot his father and strangled his mother. His grandmother was fatally injured when their house exploded after Yowell opened a natural gas line.
Yowell had tried to delay his execution, the 14th this year in America's most active death penalty state, by joining a lawsuit with two other condemned prisoners that challenged prison officials' recent purchase of a new supply of pentobarbital for his scheduled lethal injection.
They argued use of the sedative could cause unconstitutional pain and suffering.
The US Supreme Court rejected the appeal.