When my sister's ex fled his home to avoid my Dad and I, she showed us where he kept his prized N A Z I war trophy pistols that he cherished so much.  Since he was using them to threaten and terrorize my sister, my Dad seized them and took them away.

Of course, her ex was absolutely outraged by this, and demanded that his pistols be returned to him.   So my Dad took an acetylene torch to both handguns, and melted them down, totally destroying them.   He dropped off the metal remains of the pistols at their house while her ex was away at work.

Anyway, he got the message, and he never touched my sister again after that.   Nor did he file a complaint with the police about his pistols being destroyed.  Thankfully, my sister  finally did file for divorce a few weeks later.

But it took her until he was actually putting a gun to her head and threatening to blow out her brains, before she finally understood that she had to leave.