He was charged with murder, but got off on a plea of insanity.

他被指控犯了谋杀罪，但以精神错乱为由逃过惩罚。

《牛津词典》

In August, federal prosecutors and a judge accepted Albrett's plea of not guilty by reason of insanity.

八月，联邦检察官和法官因阿尔布若特精神错乱，接受了其无罪的抗辩。

youdao

Analysts initially expected Mr Holmes to enter a plea of not guilty by reason of insanity.

BBC: Aurora shooting: Not guilty plea entered for James Holmes

So she entered a plea of not guilty by reason of insanity.

NEWYORKER: A Loaded Gun

In court documents, Holmes' attorneys had suggested that they might enter a plea of not guilty by reason of insanity for the shooting rampage at the theater that left 12 people dead and 58 injured on July 20, 2012.

CNN: Judge enters not guilty plea for accused theater shooter