In the eighteen years since its launch Craig's list has grown from a small collection of San Francisco job postings. To a global marketplace the destination from millions interested in buying and... See More
In the eighteen years since its launch Craig's list has grown from a small collection of San Francisco job postings. To a global marketplace the destination from millions interested in buying and selling everything from -- operators. To Cuisinart at its best -- for backyard commerce. At worse an online pot shop for thieves looking to unload stolen goods. Tonight ABC's Neal Karlinsky follows a team of police specialists dedicated to busting Craigslist crimes. What you're seeing his two armed men holding up a pawn shop in broad daylight. Masked gunman taking jewelry right out of the case. And here three burglars caught on tape inside a home taking everything -- in the last few weeks a rash of burglaries across the country. But it's just the beginning there are nearly a thousand robberies a day nationwide according to the most recent figures. And it's much more than just bank robberies it's everything and it's big business for the bad guys. But fencing all this stolen stuff just got a little more tricky. Inside this cramped office at the Portland police department -- shopping spree never -- If you're thinking right about now this isn't your average burglaries a lodge your right -- the price on -- These detectives spend their time jamming MC hammer and surfing the web. Sending text messages from disposable so called burger phone. And sending emails from phony accounts many couples donors and an -- a little and -- All part of one of the strangest shopping sprees you'll find yourself on the 16100000300. Dollar so when they're responding to ads on Craig's list for everything from computers to guitars motorcycles. I got -- message then you've done that in years school ms. Aren't right now welcome you think it's yours. -- -- You name it they're looking for it but they're really only shopping for one thing. Bad guys unloading stolen merchandise. The range of stolen items they've recovered is staggering where Bob back to cast as soaring. Droid cell phone we tag along as they go undercover -- They've got a meeting with a seller rebut top of the line mountain bike they suspect is stolen and they're about to do the -- -- the seller arrives with the -- but they don't let on right away first they make sure it's real lead he's stolen bike Roger were coming it is. And detectives try to decipher how this guy who goes by the name LT ended up with there was another primary -- lose federal. We were this period. But detectives can't prove that Alfie actually stolen so they confiscate the body got another -- And after a tough grilling they cut him loose. Relieved he's not going to jail LT a guy police say is no stranger to handcuffs tells us Craig's list is best thing that ever happened. -- Americans have your own business. That won't come on they're letting you off we can be honest here are these guys none of them think you didn't know you were dealing -- a stolen by its I had bought in better homes and numbers. And then. And then there's insisted -- had to give away. Craig's list is a booming marketplace where regular people make on this deals to sell every day things but police say it's also become. -- pawn shop for stolen goods. Rather pot shops in Portland there. Well regulated than they don't really have a time the property go to pot shops anymore detective Steve Anderson and -- -- -- and -- -- unit grew out of an overwhelming demand. What immunity or -- case in point to opt for a horses lead driven pair of new parents victims of a stolen -- beast roller who set up the road meeting with a suspected thief. Even went so far is to take this video on their cell phone. Data show -- the threat here. This -- still baby strollers. They put up flyers -- around and found out their neighbors were hit two and their strollers were all turning up on Craigslist. Tell anybody. -- -- -- -- From people emailing me twining that I know it -- a lot more. Still their success rate is high more than a hundred deals in six months driving to their next case there's no mistaking it. There -- room a stolen trailer that a man had in his Stanley for a 35 years. Turned up for seal and was -- perfect match when detectives arrived I walked up and within a matter ten seconds. To see all those different things from from the from a -- into the back. Which says that's his trailer this time the victim mark -- -- is they're just a few minutes later to make up positive identification. Got a little twist that you mention it. Video here. The -- rebel. Things like that -- -- -- told us he'd been checking Craigslist every week for five straight months to get to this point. I always figure -- some business. -- that are sold them. And try to make -- dealer booklet figured the best place -- on Craig's list and you just spotted -- -- -- with this morning and before sundown. He got back -- and they. -- bet on -- listening to a three days. The man who is trying to sell it is now a victim too he didn't know what was stolen when he bought it and now it's gone. I'm surprised they are pretty good sport I mean here it is -- you you know you're out 300 box. And I've had worse really I mean people always stealing from other people unfortunately that's why -- added -- that my friends what would you say to those who sailed on him. It's pretty small scale stuff we really need only detectives now. Oh including guitars ungrateful you have to go after the criminals but you have to go after worthy -- -- property. Because if they don't have an outlet to sell it. Then the don't have a way of making money so mid may discourage crime. When the music stops this shopping spree between cops and robbers isn't about deal. Sometimes it's about sending a victim home with its precious belongings. And letting the bad guys know that when it comes to fencing their goods. Solar -- Thanks. I'm Neil -- -- for Nightline in Portland Oregon.
This transcript has been automatically generated and may not be 100% accurate.