Attorneys for a Missouri inmate scheduled to be put to death next week for a triple killing more than two decades ago are pressing a federal judge to block the execution, citing the man's brain tumor.

Attorneys for Ernest Johnson say in a lawsuit last week in U.S. District Court in Kansas City, Missouri, that his "unique medical condition" could be exacerbated by lethal injection, possibly causing uncontrollable seizures and convulsions.

The state counters that Missouri has carried out 18 "rapid and painless" executions since late 2013, and that 55-year-old Johnson's appeal wasn't filed timely enough.

Johnson is to be executed Nov. 3. He was convicted of bludgeoning Mary Bratcher, Mable Scruggs and Fred Jones with a hammer in 1994 at a Casey's General Store where they worked in Columbia.

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