Whether inmate mentally fit for execution could cause delay

In this 1998 photo, Wesley Ira Purkey, center, is escorted by police officers in Kansas City, Kan., after he was arrested in connection with the death of 80-year-old Mary Ruth Bales. Purkey was also convicted of kidnapping and killing a 16-year-old girl and is scheduled to be executed on July 15, 2020, in Terre Haute, Ind. (Jim Barcus/The Kansas City Star via AP)

CHICAGO — The man next on the list to be executed by the federal government after a nearly 20-year hiatus ended this week might have a better chance of avoiding lethal injection, legal experts say, because he suffers from dementia and so, his lawyers say, can no longer grasp why he’s slated to die.