william holbert and his wife received threats in prison.d in the jail that brings me a cell phone and gives me threats on my life and my wife's life. i'm a dead man, that's not important. but my wife don't deserve this. >> you talk to your lawyers about this? what are the options they have? >> options? what options? excuse me. just give me a second to compose myself. ? it's a really, really bad guy. doesn't get worse than this kind of a guy. he is the worst of the worst. >> do you think the trail of bodies is longer than we know? >> i have no doubt. exactly how many people did he kill? nobody knows. >> panama's auxiliary prosecutor says he's reaching out to other countries to see if any of their missing persons may have crossed paths with wild bill. >> translator: once they verify and confirm any persons that had contact with him and have disappeared, they'll take measures to verify where they are. >> if there are other victims out there, they may be hard to find. wild bill mostly targeted loners, people's whose disappearance may not be not