Not a bad theory. Unfortunate we can’t hear his side of the story. I have a feeling it would sound quite like the rest of these.

https://www.courthousenews.com/sister-of-american-sniper-killertold-him-i-hate-your-demons/

Weed was the last witness to be called Wednesday. She appeared to bolster Routh's insanity defense when she testified that Routh told her he was hearing voices and "seeing things" before the murders.

https://allthatsinteresting.com/herbert-mullin

https://www.the-sun.com/news/4732460/kill-murder-the-voice-god-yorkshire-ripper-peter-sutcliffe/

https://people.com/crime/texas-man-craig-vandewege-murder-wife-son-voices/

https://people.com/crime/mari-gilbert-killed-daughter-sarra-had-schizophrenia-attorney-says/

https://www.abc.net.au/news/2021-06-22/mohammed-ibrahim-stabbing-rampage-coronial-inquest/100235174

https://www.nytimes.com/2004/01/14/international/killer-of-swedens-foreign-minister-tells-of-hearing-voices.html

https://www.telegraph.co.uk/news/uknews/9706442/Child-killer-who-heard-voices-almost-invisible-to-experts-inquiry-finds.html

https://www.texastribune.org/2016/04/06/killer-faces-execution-boys-death/

Coincidence?

https://ultraculture.org/blog/2014/06/06/hearing-voices-military/