Bill > H4016

This bill introduces a comprehensive framework for incorporating neuroscience evidence, particularly regarding fight or flight responses, in criminal proceedings in Massachusetts. The legislation defines "fight or flight response" as an involuntary physiological reaction that can temporarily overwhelm a person's ability to reason, control their actions, or exercise judgment during a perceived threat. The bill allows neuroscience evidence to be admissible in criminal cases to demonstrate how these involuntary responses might impact a defendant's criminal liability, intent, or culpability. In self-defense cases, defendants can now introduce scientific evidence showing that their fight or flight response made it cognitively impossible to avoid physical combat or use proportional force. The bill requires courts to provide jury instructions explaining how neuroscience evidence relates to legal standards of criminal responsibility, and shifts the burden to prosecutors to prove that a defendant's actions exceeded what was objectively necessary when such cognitive limitations are demonstrated. Importantly, the legislation emphasizes that it is not creating a new affirmative defense, but rather expanding the scientific understanding of human behavior in legal proceedings by allowing more comprehensive evidence about neurological functioning to be considered during trials.

Justice

https://malegislature.gov/Bills/194/H4016