Updated

New Jersey on Monday became the first state to enact "smart gun" legislation that would eventually require new handguns to contain a mechanism that allows only their owners to fire them.

The law will not go into effect immediately because the technology is still under development and it could be years before it becomes a reality. But supporters hailed it as an important milestone in the campaign to reduce handgun deaths.

"This is common-sense legislation. There are safety regulations on cars, on toys. It's clearly time we have safety regulations on handguns," Gov. James E. McGreevey said at Monday's bill signing ceremony.

The New Jersey Institute of Technology is developing a smart gun prototype that would use sensors on the pistol grip to identify a user.

The owner would have his grip programmed at a gun shop or police range by practice-firing the weapon. A microchip in the weapon would remember the grip and determine in an instant whether the authorized user was holding the weapon. If not, the gun would not fire.

Under the New Jersey law, the technology will be required in all new handguns sold three years after the state attorney general determines a smart gun prototype is safe and commercially available. Weapons used by law enforcement officers would be exempt.

Supporters say the law will help prevent accidental gun deaths and suicides.

The legislation "will soon cause the gun industry to forever change the way it designs and manufactures its products," said Bryan Miller, executive director of Ceasefire New Jersey.

But opponents argued that it makes little sense to legislate about a technology that does not yet exist and have raised questions about its reliability.

"No technology is foolproof," said Nancy Ross, spokeswoman for the Association of New Jersey Rifle and Pistol Clubs. "Anyone who has a computer knows how many times it crashes."

NJIT researchers say a viable smart gun prototype can be developed in about two years with $4 million to $5 million more in funding.

"What we have is a demonstration concept," said Donald Sebastian of NJIT. "It is not yet a proven technology."

Gun manufacturer Smith & Wesson was awarded a $1.7 million federal grant last year to work on developing the technology and has spent $5 million on development since 1993.

The smart gun concept first started to receive attention in New Jersey when Jacob Locicero of Hawthorne, whose daughter Amy was murdered in 1993, approached Assemblywoman Loretta Weinberg, D-Bergen, about it six years ago.

Over the next several years, gun control groups, including Ceasefire New Jersey and the Million Mom March, made it their top legislative priority.

But the legislation was consistently blocked in the Republican-controlled Assembly, where former Assembly Speaker Jack Collins, R-Salem, called the bill "intellectually vacuous." This year, Collins' retirement and the transfer of political control of the lower house to the Democrats paved the way for passage.

"It's a beginning," Locicero said of Monday's bill signing. "I don't think that any law is ever the panacea that everybody thinks it's going to be, but it does provide an opportunity for tragedies not to happen."

Similar bills have been introduced in other states, including New York, Ohio, Tennessee, and in Congress.