If you have defended an assault case based on self-defense, you know that the alleged victim’s character for violence can be relevant. What about on direct?
If your client knows of prior acts of violence then he may have a better argument that it was necessary to use, perhaps, more force than if the client knew the victim to be a peaceful person.
Mil. R. Evid. 405(a) allows the opinion of a victim’s character trait for violence. 405(b) would appear to support specific acts regarding that trait of violence.