DENVER (AP) — Police stations in Denver are accepting bump stocks from residents after the city imposed a ban the devices.

Bump stocks allow semi-automatic rifles to mimic the rapid fire of machine guns when attached.

In the wake of last year's Las Vegas mass shooting, the Denver City Council made bump stocks illegal to sell, carry, store or otherwise possess within the city. Violators can be fined up to $999 and face up to 180 days in jail.

The move was largely symbolic as the city has long prohibited the types of semi-automatic rifles that can be modified by the device.