First, he wore that pullover jacket a lot. There are several photos of him in it. And you can deduct what a person took with them by taking inventory of what's left behind.
Bank records would show whether he recently withdrew any money.
My daughter carries her passport as ID. She carries it everywhere. For months while she was without a driver's license, she used her passport.
If one of my kids went missing and left the car behind, one of the first things my husband would do is retrieve the vehicle - for a variety of reasons - mostly so it would not be towed but also to preserve evidence if the car contained any. His parents are judges who probably don't stop thinking like judges in their daily lives.
If I just found out my SO had done something criminal, we would be having a "heated" discussion rather than an emotional one.