A Massachusetts law banning possession of bump stocks and other accessories that increase a guns rate of fire went into effect on Thursday, making the state the first to enact such legislation in the wake of last years deadly mass shooting in Las Vegas.

Bump stocks allow semi-automatic rifles to simulate automatic fire. The accessory replaces a standard rifle stock the piece that rests against the shoulder and harnesses a weapons recoil to slide the gun rapidly back and forth onto the shooters trigger finger, firing each time.

The gunman who opened fire on tens of thousands of concertgoers in Las Vegas last October had attached bump stocks to at least a dozen assault-style rifles, law enforcement officials said. He was able to shoot more than 1,100 rounds over the span of a few minutes, killing 58 people and wounding 422. More than 400 others were injured in the chaos caused by the shooting.

We saw in Las Vegas the carnage, which far exceeded the carnage of any other mass shooting in U.S. history, and it made it very clear to me that theres no purpose whatsoever for a bump stock, other than killing a lot of people very quickly, said John Rosenthal, founder of Stop Handgun Violence, a Massachusetts-based nonprofit that advocated for the measure.

Bump stocks should be banned, and I am proud of Massachusetts to be the first state in the nation to do the right thing, he said.

California and New York had banned the devices before the Las Vegas shooting.