Interestingly, I just saw a post claiming:

According to NY legal code, it is not murder if:

The defendant acted under the influence of extreme emotional disturbance for which there was a reasonable explanation or excuse, the reasonableness of which is to be determined from the viewpoint of a person in the defendant’s situation under the circumstances as the defendant believed them to be.

Given how composed they are and premeditated it was, I’m not sure if this is in the spirit of the legal clause, but it could be… interpreted liberally by a judge.