A South County man indicted by a federal grand jury in 2015 on weapons and marijuana charges was set to be sentenced today after taking a plea agreement. But Craig Mason’s sentencing has been postponed until mid-November, because a different case currently being litigated could invalidate the weapons charge.

Mason pleaded guilty in March to unlawfully manufacturing and dealing in firearms and was facing as much as five years in prison and a $250,000 fine, according to court documents. At the center of the charge was an allegation that Mason manufactured and sold the parts necessary to assemble a firearm to a person he believed to be a felon.

But in a memo sent last week to U.S. District Court Judge Kimberly J. Mueller, Mason’s attorney cited developments in a case involving similar allegations — United States v. Roh. Like Mason, Roh was indicted for manufacturing and dealing firearms — hundreds of AR-15-type lower receivers, completed pistols, and completed rifles, according to court records.

At issue is whether “lower receivers” can be considered firearms. Federal prosecutors have, as in Mason’s case, considered the answer to be “yes.” Mason operated a workshop on his Rosewood Road property just outside Lake of the Pines, where he allegedly converted AR-15-style blanks into lower receivers. A “blank” is a metal casting that can be converted to allow the firing a of a projectile. Once converted, it is considered a firearm by statute, even if there is no barrel, handle, or trigger, and it is subject to regulation.

In Joseph Roh’s case, a judge ruled “the evidence at trial was uncontroverted that a finished AR-15 receiver does not contain a bolt or breech block and is not threaded to receive the barrel. … The plain conclusion is that the finished receiver is not a firearm.” The ruling continued, “Roh did not violate the law by manufacturing receivers. The Court further finds that with respect to manufacturing receivers, the statute and regulation are unconstitutionally vague.”

Following the tentative order, the prosecution and defense agreed to a deal in which Roh would plead guilty to the charge against him, but would be allowed to withdraw that plea if he stayed out of trouble for a year. Prosecutors would then dismiss the case. If Roh abides by the deal, he will have no criminal conviction and serve no time behind bars. Roh’s sentencing has been set for July of next year.

What led to Mason’s arrest

The Bureau of Alcohol, Tobacco, Firearms and Explosives had been investigating the unlawful sale and manufacturing of firearms by Sacramento dealer LCG AR Parts and Custom Accessories. A confidential informant reportedly purchased blanks from LCG in 2013, asked to have them illegally converted and was directed to Mason. According to court records, Mason manufactured two AR-15-style lower receivers for the confidential informant, despite being told the man had been to prison and was prohibited from possessing a firearm.

During execution of a federal search warrant on Mason’s property in October 2013, law enforcement officers reportedly found multiple AR blanks and lower receivers, as well as several AR-15 rifles and a pistol built with a lower receiver that originally had been blanks, and three jigs used to machine blanks into lower receivers.

They also allegedly found an active marijuana grow with 24 mature marijuana plants ranging in size from 2- to 7-feet tall. Inside the garage, law enforcement discovered an active marijuana processing operation including 15 drying lines containing five pounds of processed marijuana, and an ice chest concealing three and a half pounds of processed marijuana, according to court documents.

Mason was indicted by a federal grand jury in 2016 and charged with unlawful dealing and manufacturing firearms and manufacturing marijuana.

Contact reporter Liz Kellar at 530-477-4236 or by email at lizk@theunion.com.