PORTLAND, Ore. (KOIN) — The Washington State Patrol held its final bump stock buyback on Monday, one day before they become illegal. Anyone with a bump stock — those devices which turn rifles into automatic weapons — is expected to either turn it in to local law enforcement or destroy it.

WSP paid $150 for every of the 1,000 bump stocks they bought back. They reached their 1,000th earlier Monday afternoon.

Troopers still collected any devices that were dropped off.

The bump stock – the attachment used by the killer during the 2017 Las Vegas massacre to make his weapons fire rapidly like machine guns – will become illegal on Tuesday in the only major gun restriction imposed by the federal government in the past few years, a period that has seen massacres in places like Las Vegas; Thousand Oaks, California; Sutherland Springs, Texas; and Orlando and Parkland, Florida.

Unlike with the decade-long assault weapons ban, the government isn’t allowing existing owners to keep their bump stocks. They must be destroyed or turned over to authorities. And the government isn’t offering any compensation for the devices, which can cost hundreds of dollars. Violators can face up to 10 years in prison and thousands of dollars in fines.

The Associated Press contributed to this report

