Execution of Marcellus Williams sparks outrage after Governor and State Supreme Court rejected bids to save him

The execution of a death row inmate whose murder conviction has been doubted by the prosecutors that convicted him has sparked a wave of outrage across the US.

Missouri Governor Mike Parson has been branded 'shameful' and 'racist' and the state and federal justice systems accused of being 'flawed' after Marcellus Williams was put to death by lethal injection on Tuesday.

Williams, 55, was sentenced to death over the 1998 killing of Lisha Gayle, who was stabbed repeatedly during a burglary of her suburban St. Louis home.