NEW YORK - As a bill to tighten gun control laws makes its way through Congress, Sen. Charles Schumer (D-N.Y.) is warning New Yorkers about a provision he worries could compromise the whole point of tougher gun laws.

The provision would require states to recognize out-of-state concealed gun permits. Currently, New York does not recognize concealed carry permits from other states. Schumer warned at a press conference today that an amendment for concealed carry reciprocity could undo "all the good that would be done by passing a background check bill."

It's tough to get a concealed carry permit in New York, but once someone obtains one, they can take their weapons just about everywhere, including on mass transit.

Laws for the permits vary from state to state, however. Some states don't require safety training courses, or a minimum age of 21. Several states do not require concealed weapon permit holders to be residents of that state, or to have clear criminal and mental health histories.

Some Nassau officials suggest that the provision could pose a problem, if enacted. "There really is no way that we are aware of that we can check if that license is valid or not, and obviously criminals get better and better at forging documents," says Pete Paterson, of the Nassau PBA.