The Indiana Department of Corrections reports that Julie Van Orden has died.
Van Orden was convicted in 1980 of the murder of former Evansville Mayor Russell Lloyd Sr.
She was 70 years old.
Officials say Van Orden died at the Indiana Women's Prison on Thursday of apparent natural causes. An autopsy has not been scheduled.
Van Orden shot Lloyd at his home after he left office. At trial, she was found guilty but insane and sentenced to 40 years.
In 2010, the Court of Appeals rejected Van Orden's appeal of another conviction in the stabbing of a psychiatric hospital worker.
She claimed prosecutors acted improperly during her trial for the 2006 attack and the jury should have determined she was insane.
One of Lloyd's six children became mayor of Evansville, 20 years later. Russ Lloyd Jr. is the current city controller and former mayor.
"My wife never met my father and of course my son would have never known him other than seeing pictures and some videos that we have," says Lloyd Jr. "It's just a really sad thing the way she really changed the course of history."