Want To Search My Brother's Computer. Worried I May Have Unknowingly Committed A Crime. Need Advice. [usa, Ny/az]

My brother (27M) and I (29M) lost our mother in October. Shortly after that, my brother got an eviction notice from the apartment complex where he lived with her. Short of it is, she was the only income, he hadn't worked in over a year, and rent wasn't paid. He got evicted, and my husband (26M) and I offered to let him come stay with us in our home in New York. He hated Arizona, wanted a fresh start, and promised he'd changed and shaped up. He had not. After a month of trying to get him to do anything to better his situation, we had enough of his laziness and entitlement and kicked him out. All legal, all above board, all in accordance with NY law, and not the subject of the post. However, we were gracious enough to let him store his valuables, including a state of the art gaming PC he built himself and multiple hard drives, at our home until he finds something permanent.

A few days later, I happened to look him up to see if he was still posting online; he may be an entitled lazy dipshit but he's still my little brother and I still felt love and duty towards him. And I found an online wiki-style article detailing potential actual crimes. Cyber stalking, including of a minor; talking to and about a minor re:sexual shit; general online harassment campaigns. Now I have no plans of speaking to him ever again, but I worry about the computer and what might be on it. What if he has CSA material on it? I mean, he sexually harassed a kid to the point that they tried to kill themselves. What if he's done and downloaded worse?

I paid to have that PC shipped to my home. I don't know what's on it. If I were to search it and find illegal stuff on it, am I liable for having unknowingly transported a potential stash of illegal material across state lines? Is it illegal to go through it? Should I go through it? Should I call local police and say "hey, I just found out my brother might have committed crimes seven years ago in another state and I worry about what might be on his hard drives?" I don't know what I should do or if there is a correct action here or if I'm on the hook. I'm not necessarily freaking out but the fact that there might be a cybercrime bomb in my guest bedroom is not a comforting thought.

TL;DR: Moved my brother into my home temporarily out of pity, kicked him out, then found out he very likely committed crimes. Now I have his computer sitting in my house and I have suspicions of what might be on it. Am I criminally liable if I find out I unknowingly paid to have a CP bomb shipped to my house???