CNN —

Marcellus Williams, whose murder conviction was questioned by a prosecutor, died by lethal injection Tuesday evening in Missouri after the US Supreme Court denied a stay.

The 55-year-old was put to death around 6 p.m. CT at the state prison in Bonne Terre.

Williams’ attorneys had filed a flurry of appeal efforts based on what they describe as new evidence – including alleged bias in jury selection and contamination of the murder weapon prior to trial. The victim’s family had asked the inmate be spared death.