Michael Bernard Bell, 54, has been lethally injected for the 1993 ambush murders of a young couple in Jacksonville mistakenly thought to include the gunman who killed Bell's brother.

A man who fatally shot two people outside a Florida bar as part of an attempted revenge killing is scheduled to be put to death Tuesday, which would be the 26th execution in the U.S. this year.

Neuroscientists and adolescent psychiatrists told the Marshall Project the kind of trauma some of the boys endured at Dozier and Okeechobee affects brain development and produces violent people.