Israel Keyes admitted to at least one of these but probably did tens if not hundreds. Had caches across the country of supplies and weapons. He was only eventually caught cause he got sloppy and I think had a body or something on his property at some point. Didn’t admit a lot to the police cause he didn’t want media attention and for his daughter to find out, a lot of information is gleaned from missing persons that coincided with where he happened to be at the time (phone pings, plane tickets, etc), and he traveled a lot.

There’s a long-running podcast detailing what is known about him, called True Crime Bullshit.