>> the metal detector that i wanted was about $600. >> are you out of your mind? >> no. >> you buy a $600 metal detector? >> uh-huh. that's even like the mid-range. you can spend upwards of $9,000 on a metal detector if you wanted to. >> you're getting toward being uppercase nerd? >> very much so, yes. >> so he figured he'd sell the gun and use the cash to buy that new metal detector. >> it's what the state of iowa calls a long gun. it's something that you put to your shoulder and you shoot like a rifle or a shotgun. so i listed it online, on armslist, it's like craiglist for guns. >> reporter: what'd you ask for it? >> $360. >> reporter: about a month later, he got a nibble via email. >> i told him that i needed cash and i needed a photo i.d. so i knew he was who he said he was, and that he was at least 21. >> reporter: who did he say he was? >> he said his name was andy wegener, and that was the email address that he had contacted me from, was andy wegener something-or-other at gmail.com. >> reporter: where'd you meet? >> i work part-time at a gas station.