Just starting down this rabbit hole but here is something:

Nashville School Shooter heard voices:

http:// wreg.com/2017/10/23/detective-accused-nashville-church-shooter-heard-voices/

Ft. Lauderdale Shooter heard voices:

https:// www. nbcnews.com/news/us-news/fort-lauderdale-airport-shooting-suspect-complained-hearing-voices-officials-n704081

(Yesterday's) Florida HS Shooter heard voices:

http:// abcnews.go.com/US/florida-school-shooter-methodically-moved-classrooms-execute-victims/story?id=53112929

Navy Shooter heard voices:

https:// www. usatoday.com/story/news/nation/2013/09/17/navy-yard-shooting-aaron-alexis/2825749/

FSU Shooter heard voices:

https:// www. nbcmiami.com/news/local/FSU-Shooter-Said-He-Heard-Voices-Coming-Through-the-Wall-283440121.html

Colorado Walmart Shooter heard voices:

http:// www. foxnews.com/us/2017/11/07/colorado-walmart-gunman-had-voices-in-his-head-caused-by-bad-lsd-trip-decades-ago-stepsister-claims.html