The 55-year-old was sentenced to death in 2001 for killing Felicia Gayle, a former newspaper reporter found dead in her gated community home.

Marcellus Williams was backed in his appeals for clemency by St. Louis County Prosecuting Attorney Wesley Bell.

In the aftermath of Williams’ execution there has been an outcry from the public due to the doubts over his conviction, especially since it was reported in August that a new development showed that the knife used in the murder was believed to have been contaminated by DNA from a prosecutor and investigator working on the case.