BOSTON — Massachusetts on Friday became the first state to impose a ban on bump stocks since the deadly shooting at a Las Vegas music festival.

An appropriations bill that included a prohibition on the devices, which are designed to make semi-automatic rifles mimic the firing action of fully automatic weapons, was signed into law Friday by Republican Lt. Gov. Karyn Polito. The Democratic-controlled Legislature gave final approval to the measure Thursday.

Polito is Massachusetts’ acting chief executive with Republican Gov. Charlie Baker on vacation outside of the state. Baker had previously expressed support for banning the devices.

Authorities investigating the deadliest mass shooting in modern American history said the gunman, Stephen Paddock, used a bump stock when he opened fire Oct. 1 from his Las Vegas hotel room on concert-goers below. Fifty-eight people were killed and hundreds more wounded.

The Gun Owners Action League of Massachusetts, an affiliate of the National Rifle Association, had sent an alert to its members earlier Friday urging them to contact Baker’s office and demand that he use his line-item veto power to separate out the bump stock ban.