It was one year ago that Marqus Hill shot and killed an unarmed teenager in Philadelphia.

Eighteen-year-old Irving Santana and two others were breaking into Hill's car. Hill shot Santana 13 times.

Before you say "justice served," consider this: Hill's Pennsylvania gun permit had been revoked. He had been charged with attempted murder and aggravated assault five years earlier. Yet, his permit to carry the gun was legal.

That's because he applied for and received a permit from the state of Florida with which Pennsylvania has a reciprocity agreement.

The loophole in the state's law allows people who have been denied a permit here to apply for a permit in Florida.

Philadelphia police said it is not uncommon to find someone with a Florida gun permit if their Pennsylvania permit has been denied. An investigation by the Florida Sun-Sentinel found that Florida had issued concealed carry permits to 1,400 persons who pleaded guilty or no contest to felony crimes. The state also gave permits to 216 people with outstanding warrants and six who were registered sex offenders.

Now a proposed federal law - the National Right to Carry Reciprocity Act (H.R. 822) - threatens to force Pennsylvania to accept reciprocity with every state. That would require states with strong gun regulations such as Nevada, which requires gun owners to complete a written exam and have live-fire training before they receive their permit, to recognize concealed carry permits from states such as Utah which have far fewer regulations.

That means someone from Florida could carry a concealed weapon in Nevada or that someone who has been denied a permit in Pennsylvania could obtain a permit elsewhere and legally carry that gun here or anywhere else.

Police and mayors across the country object to the change. They argue - correctly - that states should have the right to regulate firearms within their jurisdictions. Pennsylvania's Constitution asserts that state law on firearms supersedes municipal statutes. This law, which has been proposed in various forms for more than a decade, would supersede state constitutional protections.

Proponents of the legislation contend states would still have the right to issue or deny permits. But what good is that if someone obtains a permit elsewhere? Under H.R. 822, introdued by Rep. Cliff Stearns, R-Fla., all states would be required to accept that person's right to carry.