If you are 100% sure it was him that took the items...
Then I'm not sure what the laws are in your state ( and you may want to check) .
Those are still legally, his things too.
He went about it pretty cowardly, yet still his things.
What I was told was.....that it is Marital property, and my spouse had every much a right to them as I did. And that I could change the locks if I wanted to, but the law stated that if she wanted something, she had every right to break down the door to get it.
And then, with a sparkle in her eye, my Lawyer told me that it goes both ways......
Just because she moved it, it was still marital property that I had a right to...
I bet you said.."yea, right" ,when you were first told that there was nothing you could say, that would shock any of us huh ?