TAMPA — For years, Florida recycling facilities have second-guessed sellers who haul in items that raise eyebrows. Large quantities of copper. Appliances. Catalytic converters. ”We don’t want to buy stolen material,” said Trademark Metals facility manager Kevin Christman. A new state law makes selling suspicious items harder. The law, which took effect Sunday, takes away the immediate cash incentive. It requires that sellers bring proof of ownership if they’re selling any one of 20 “restricted metals.” ”Hopefully these kinds of changes will dissuade people from bringing stolen property,” said St. Petersburg police spokesman Bill Proffitt. The list of restricted metals includes air conditioning unit parts, shopping carts, grave markers and anything with a government logo — items thieves target. People selling those things must provide a driver’s license or federal ID card with a street address (not a post office box). Then, the sellers have to wait for the metal facility to mail a check to that address or deposit the money directly into their bank account. Sellers also must provide proof of ownership, such as a receipt or bill of sale. The new law was pushed by law enforcement and the Florida Recyclers Association, which wanted a uniform statute that would hold recycling facilities to the same standard, said Hillsborough sheriff’s Detective Greg Pollock. Any metal recycler who intentionally violates the law commits a felony. Selling stolen metal is a felony, too. In Tampa Bay, it’s a problem authorities have battled for years. About five years ago, Tampa police started seeing a rise in stolen air conditioning units, said police Detective Dan Hinsz, who has investigated metal theft for about 10 years. It’s especially awful, authorities say, because while the thief usually gets only between $30 and $50, the homeowner must pay upward of $1,000 to replace the unit. Hinsz estimates metal thefts cost Hillsborough residents and businesses at least $1 million each year. It has cost Sam Gray several thousand dollars. Gray, 50, rents homes across Hillsborough and says parts from five AC units have been stolen from him over the past three years — plus parts from the two units at his own home. He has a $1,000 insurance deductible, which he’s had to pay each time, and he knows the insurance company has had to pay up for the replacement units, which cost between $3,000 and $5,000. ”The joke around the neighborhood is that you’re better off putting a $50 bill on your air conditioner with a note that says: ‘Leave my air conditioner. Here’s 50 bucks,’ ” Gray said. A detective explained the new law to him shortly after it passed, Gray said, and he’s hopeful it will make a difference. ”I like the idea that they’re not going to give them cash right away,” he said.