PEABODY – Police say collaboration between Peabody and Burlington police captured a con artist Friday who tried to sell innocent victims merchandise he never had.Robert Diaz, 48, of 408 Saratoga St., East Boston, was arrested and charged with larceny over $250 by false pretenses, forgery of a document and giving a false name to police.Diaz, who a police spokesman says has a “lengthy criminal history,” allegedly contacted a businessman and stated that his brother works for a Sears and manages overstocked items. Diaz, who said his name was “Henry,” told the victim that he would sell him a 50-inch plasma television for a discounted price, around $3,000, police said.Lt. Dennis Bonaiuto pointed out that the criminal wasn’t smart because plasmas have gone down in price over the past couple years.”It’s kind of crazy,” Bonaiuto said. “It’s really not a deal at all.”In any event, Bonaiuto says these types of situations usually end with the victim losing thousands of dollars.”Unfortunately when these types of scams are successful, people end up losing a large amount of money,” Bonaiuto said.Typically, the victim will meet the suspect in front of a mall. The suspect will obtain the victim’s cash and tell them that he is about to obtain the television from the rear of the store, but never returns.”We want to warn the public,” Bonaiuto said, “if they are contacted in any unusual way to purchase a larger ticket item and the transaction does not take place in a showroom or a reputable dealership, then they should refuse to be involved in the transaction. Most likely it’s going to be a scam.”In this case, the suspect arranged for the transaction to take place at the Burlington Mall. But at the last minute, he changed the location to the North Shore Mall and said to meet on Friday.The near-victim was fortunate enough to be familiar with this particular scam. He contacted Burlington police, who in turn contacted Peabody detectives.Police conducted a stakeout outside the North Shore Mall on Friday and watched the suspect approach.”At the designated time, the suspect approached the vehicle being used by police,” Bonaiuto said. “As the transaction unfolded the detectives moved in and placed the suspect into custody after a brief struggle.”