Missouri death row inmate Marcellus Williams was executed by lethal injection on Tuesday for the 1998 murder of Lisha Gayle, a former journalist who was fatally stabbed in her home near St. Louis.

Williams, 55, was pronounced dead shortly after 6:00 p.m. CDT at a state prison in Bonne Terre, Missouri, about 60 miles southwest of St. Louis, his lawyer confirmed to ABC News.

The case attracted national attention as Williams consistently maintained his innocence. The victim’s family opposed the execution, and his legal team filed multiple appeals.

“Marcellus Williams should be alive today. There were several points when a decision could have spared him from the death penalty. The death penalty should never be an option if there’s any doubt about innocence. This outcome failed justice,” said St. Louis County prosecutor Wesley Bell in a statement after the execution.

The U.S. Supreme Court denied two final appeals to stop the execution, just an hour before it was carried out. Justices Ketanji Brown Jackson, Elena Kagan, and Sonia Sotomayor dissented from the ruling.