Is the Bureau of Alcohol, Tobacco, Firearms, and Explosives overstepping its bounds in banning bump stocks? Is the agency wrongly defining lower receivers for AR-15’s as “firearms,” and if so, what does it mean for hundreds if not thousands of cases decided over the past 50 years?

These are some pretty big questions, and we try to tackle them on today’s Cam & Co. with the help of Caleb Kruckenberg of the New Civil Liberties Alliance, which is representing Utah resident Clark Aposhian in his bid to overturn an ATF rule retroactively banning bump stocks after the agency had, for several years, determined that the items were lawful.

Kruckenberg says the lawsuit isn’t about whether or not bump stocks are protected under the Constitution, but about whether the agency had the authority to do what it did, or whether it was up to Congress to ban bump stocks through legislation. As the New Civil Liberties Alliance put it last June, when it filed an appeal with the 10th Circuit:

Rightly or wrongly, Congress has not yet prohibited bump stocks. But when a deranged gunman opened fire on a crowd in Las Vegas, Nevada on October 1, 2017, using weapons equipped with scopes, 100-round magazines and bump stocks, a legislative response certainly could have been considered. What transpired instead was a Bump Stock Final Rule banning the devices—an administrative shortcut by ATF that violates basic constitutional principles concerning who makes the law. Even if ATF’s goal is laudable, this Court has a constitutional obligation of its own to strike down the administrative agency’s attempted legislative rewrite. Otherwise, the Executive Branch will usurp Congress’ legislative function in other areas, and the Constitution’s careful limits on how laws are made will be undone.“The ATF has attempted to rewrite the law and declared that as many as 500,000 Americans are now federal felons even though they lawfully purchased bump stocks with the ATF’s prior approval. The Constitution doesn’t allow prosecutors to change the criminal laws to suit their sense of what the law should say. The bump stock ban threatens to set a dangerous precedent that prosecutors, not lawmakers, have the final say about what makes something a crime.

We also spend some time on today’s show delving into the story of Dan O’Kelly, a former ATF agent who’s now serving as an expert witness and a whistleblower who says the agency has been wrongly interpreting the definition of a firearm in federal statutes for years, and has helped get several cases tossed out of federal court in recent years.

As O’Kelly sees it, the ATF has been deliberately misinterpreting a key gun control regulation for decades because officials fear that following the letter of the law would allow criminals to build AR-15s and other firearms piece by piece with unregulated parts.

He said he voiced his concerns to an ATF official two decades ago, but was rebuffed.

Now, however, his view is gaining traction in courtrooms around the country.

In December, a federal judge in Ohio dismissed weapons-related charges against two men after O’Kelly testified that the

AR-15 part at issue in their case was not subject to federal law or regulation.

US District Court Judge James G. Carr for the Northern District of Ohio called the ATF’s long-standing interpretation of the regulation “unreasonable and legally unacceptable.”

In wake of the dismissal, then-US Attorney General Loretta Lynch wrote a letter to Congress outlining the issues. She advised lawmakers that the judge’s order was not suitable for appeal and that if ATF officials believed the definition of a receiver should be changed, they should pursue regulatory or administrative action.