It's now illegal in New Jersey to sell or posses a "bump stock," the controversial firearm accessory allegedly used by the gunman in last year's Las Vegas massacre.

Gov. Chris Christie, a Republican set to leave office Tuesday, signed a Democratic-sponsored bill Monday outlawing the devices, which can be affixed to semiautomatic riffles to allow them to fire bullets, mimicking automatic weapons.

Christie -- who took action on more than 150 bills on his final full day in office -- made no statement on the legislation (S3477/A5200), which takes effect immediately.

Anyone who owns a bump stock or "trigger crank" now has 90 days -- until April 15 -- to surrender the accessories to law enforcement authorities. Retailers who sell them have 30 days.

Sale or possession of a bump stock is now a third-degree crime that carries a sentence of three-to-five years in prison, a fine of up to $15,000, or both.

Technically, bump stocks were already restricted by state law in New Jersey. You could own a bump stock but were not allowed to affix it to a weapon or be in the vicinity of a weapon. This law, however, institutes an outright ban.

"These are simple, easy-to-use devices that increase the firepower and killing power of firearms," said former state Sen. Raymond Lesniak, D-Union, who sponsored the bill before he retired last week. "There is no legitimate need for these devices."

The shooter in the Las Vegas massacre in October-- which left 58 people dead and more than 500 more injured -- had 12 of bump stocks in his hotel room, authorities said. That ignited a heated national debate about the accessories.

Christie -- who has long been opposed to tightening New Jersey's already strict gun laws -- said shortly after the shooting that he'd be open to further restrictions on bump stocks.

The Democratic-controlled state Senate voted 28-0, with 12 abstentions, to pass the bill. The Democratic-controlled state Assembly voted 60-0 to pass it.

Brent Johnson may be reached at bjohnson@njadvancemedia.com. Follow him on Twitter @johnsb01.