After Stephen Paddock opened fire on concert-goers from his room in the Mandalay Bay Hotel in Las Vegas on October 1, 2017, killing 58 people, the question, other than what his possible motive may have been, seemed to go to how could one man commit so much carnage in such a short time frame, on his own?

The answer apparently lay with what was found in his room: bump stocks.

Bump stocks replace the standard AR and AK-style rifle stocks and use the natural kickback of the initial shot to speed shooting. Paddock had rifles in the room that were fitted with bump stocks.

Now, the Justice Department’s Bureau of Alcohol, Tobacco and Firearms and Explosives is making moves towards regulating those bump stocks.

The ATF said it plans to quiz makers, gun sellers, users and the general public on the special stocks easily added to AR-style rifles that are currently unregulated. But in its notice, the ATF did not indicate that it is considering a ban. It had previously said that it would not regulate the devices.

Even the NRA has expressed that there should be additional regulations attached to ownership of bump stocks, noting that the devices are designed to make semi-automatic firearms operate as fully automatic weapons.

Should these new regulations become a thing, getting your hands on bump stocks could become more difficult.

In its notice, ATF said, “Following the Las Vegas shooting, a significant amount of public attention has been focused on bump stock-type devices. ATF has received correspondence from the general public and from members of both houses of Congress requesting that ATF reexamine its past classification decisions concerning bump stock devices to determine whether they should be classified as machineguns…” It added that its move is “the initial step in a regulatory process to interpret the definition of machinegun to clarify whether certain bump stock devices fall within that definition. If, in a subsequent rulemaking, the definition of machine gun under section 5845(b) is interpreted to include certain bump stock devices, ATF would then have a basis to re-examine its prior classification and rulings.”

Manufacturers are being asked if regulations would harm their bottom line, and if bump stocks would benefit police officers and the military.

There’s no word on when any planned regulations could go into effect.