‘Pro-mass shooting’ suspect pleads guilty to machine gun possession

A man who was arrested last year in Savage and is accused of preparing for a violent battle with police has pleaded guilty to a federal charge.

The U.S. Attorney’s Office says 21-year-old River William Smith pleaded guilty Tuesday to possession of a machine gun.

The attorney’s office says concerned citizens told the FBI in September about Smith’s disturbing behavior at a gun range. Over the next couple of months, court documents state that Smith started talking with an FBI confidential source through social media and said he is “pro-mass shooting” and sympathized and admired past school shooters.

RELATED: ‘Pro-mass shooting’ suspect arrested in Savage had machine gun, wanted to ‘fight the police’

Federal authorities also learned Smith had access to an AR-style rifle, handguns, body armor and a Kevlar helmet, and he studied his “enemy” by watching police bodycam videos of shootings.

According to federal prosecutors, Smith asked a different confidential FBI source for auto sears on Nov. 17, hoping to make his AR-15 rifle and handguns into fully automatic weapons. He then bought the auto sears from the informant on Nov. 28 and also asked about grenades, which he then bought from the source in December.

Smith was arrested during a scheduled meeting between him and the confidential source.

His sentencing date hasn’t yet been scheduled.