OKLAHOMA CITY (AP) - A new state law may provide new deterrence against thieves who rob grave sites of metal objects, according to Oklahoma cemetery industry leaders.

A portion of the measure, signed last month by Gov. Brad Henry, requires sellers to provide proof, such as a receipt, that they legally obtained any item coming from a grave marker or stamped by a cemetery.

It also requires more stringent record-keeping in general from buyers, no matter the source of the metal. The new law goes into effect Nov. 1.

“It's something that's emotional,” said Tim Rolfs, the Oklahoma City market director for Dignity Memorial, which operates seven cemeteries in the metro area. “You're talking about the site of a loved one.”

Cemetery operators say they've been fighting thefts of bronze vases on grave markers for several years, coinciding with a sharp rise in copper prices.

Copper prices had been under a dollar per pound for decades but rose sharply about four years ago, according to MetalPrices.com. Now, the price hovers between $3 and $4 per pound, according to the Web site, which tracks copper prices.

Christina Ford, general manager for Resurrection Memorial Cemetery in Oklahoma City, said 580 copper vases were stolen from the cemetery during two months in 2005.

Industry leaders say their vigilance and the new law have already had an impact.

Out of a dozen cemeteries contacted by The Oklahoman, only Ford's reported thefts had increased during recent weeks.

“Eventually, thieves might find a way around it,” said Monty Rouse, a board member of the Oklahoma Cemeteries Association. “But I think it's working now, and I think it will work in the future.”