U.S. Attorney General Jeff Sessions has ordered federal agencies to pursue people who “lie and try to buy” firearms, ramping up enforcement on people who are already supposed to be prohibited from buying guns and ammunition.

In a written statement, the Justice Department pledged “swift and aggressive” prosecutions of felons, domestic abusers and the mentally ill who try to purchase guns from federally licensed firearms dealers.

The Department of Justice is targeting a problem identified in investigations by KING 5 and public radio’s Northwest News Network.

Those reports showed that around 4,000 people in Washington fail criminal background checks each year when they try to purchase a firearm. In many cases, the purchaser lies on the federal purchase form –- a “lie and try to buy” attempt –- which is against state and federal law.

However, the news organizations could find no instances of local or federal authorities investigating or prosecuting those cases.

Sessions has ordered federal prosecutors nationwide to pursue criminal cases against those “prohibited buyers" as part of a package of new proposals “…aggressively prosecuting federal gun laws.”

Last year, Washington state lawmakers passed House Bill 1501. It addressed several of the issues identified in KING 5’s investigations. For instance, the Washington Association of Sheriffs and Police Chiefs (WASPC) now reviews attempted firearms purchases by prohibited buyers and forwards the most serious cases to police agencies for follow-up.

Timothy Smythe of Bremerton was arrested by the Kitsap County Sheriff’s Office after receiving an alert from WASPC about his attempted purchase of an AR-15 rifle. Records show he failed background checks at two gun stores because of a robbery conviction from Hawaii.

In Washington state, the background check system is split between state and federal agencies.

For handgun purchases, the local police conduct the background check at the request of a federally licensed firearms dealer. As part of that process, police run the buyer's name through the FBI’s National Instant Criminal Background Check System (NICS), and they check local court and mental health records.

For a rifle purchase, the gun dealer checks directly with the FBI with conducts the NICS check only.

Handguns are more commonly used in crimes, so the background check is more rigorous in Washington state.

Sessions' announcement means that local law agencies can expect more help from federal prosecutors and agencies like the Bureau of Alcohol, Tobacco and Firearms to assist in “lie and try to buy” prosecutions.