Are those different checks? You said you recently sent checks by mail and they got lost in the mail and they someone checked them. Are those the same checks?

Scammers are really hard to catch. And they usually don’t work alone, which makes it ever harder.

I don’t know if they get caught. Some do and some don’t. You aren’t responsible for the amount though and banks would reinstate it. I don’t suggest you accuse anyone but you should have a police report done and let them investigate.

No matter how careful you are, scammers find the way. But as a step one you should hide your checkbook and your cards when you have strangers in the house.