BONNE TERRE, Mo. (AP) — A Missouri man has been put to death for fatally stabbing an 81-year-old woman nearly three decades ago, the first U.S. execution since the coronavirus pandemic took hold. Walter Barton was put to death by lethal injection Tuesday. Barton had long maintained he was innocent of killing Gladys Kuehler, and his case was tied up for years due to appeals, mistrials and two overturned convictions. Concerns related to the coronavirus caused several states to postpone or cancel executions over the past 2 ½ months. Until Tuesday, no one had been executed in the U.S. since Nathaniel Woods was put to death in Alabama on March 5. Ohio, Tennessee and Texas were among states calling off executions. Texas delayed six executions due to the pandemic.