I think some have fantasies, but most never speak a word of it because there is something about saying it aloud that takes an extra step in the fantasy, per say.
I think anyone who has someone that angry and then threatens your life, those words should be taken seriously. Those are serious words about a serious event. The fact that he is still struggling with this anger could mean that he has taken it internally because of the current legal situation of the charges. Be very careful with this.
Is he in IC? This would be the best case scenario for the both of you. He can document his progress and you can feel safe. Also, the courts always want to see the gradual change in the individuals and this would also help his case.