That is frightening and very creepy.
Whatever you do don't watch "Web Of Lies" on Investigation Discovery. It'll scare the hell out of you on what can happen with strangers online in this type of situation.
I'ld consult the police on not only what to look for if this dude shows up since you and your wife don't know what he looks like, but how far to go if he does. Stalking is a bit difficult to prove to police at first. There needs to be a pattern of escalation and evidence to prove it.
You might look up who he is online since you have his name and maybe find a picture of him, but there are sites he can subscribe to that can tell him if someone is looking him up.
Then again this may be nothing.