HADDON TOWNSHIP, NJ (CBS) – A Haddon Township man and known member of an anti-government extremist group has been arrested for the illegal possession of numerous firearms.

Gregory Gawrysiak, 46, was arrested on Thursday morning at his home on Emerald Avenue.

Gawrysiak, an apprentice linesman for Amtrak and a member of the Sovereign Citizen Movement, came to the attention of law enforcement in 2010. At that time, police obtained a firearm from Gawrysiak after he made threats to kill officers. No criminal charges were filed, but Gawrysiak forfeited his firearms investigation card and thus, his ability to purchase guns in New Jersey.

In the fall of 2012, the Prosecutor’s Office Homeland Security/Counter-Terrorism officer and Haddon Township Police conducted an investigation into the Sovereign Citizens Movement, a group that argues federal and state governments lack legitimate authority. Officials also learned of Gawrysiak’s involvement with the group and decided to further investigate.

During a three month long investigation, it was determined that Gawrysiak had obtained a fake Pennsylvania driver’s license in 2011 and was continuing to purchase guns in that state.

During Thursday’s arrest, officers found a pistol at Gawrysiak’s home, and relatives lead them to another handgun, a shotgun and a rifle belonging to the suspect but being kept at another residence in Mantua. All of the weapons are thought to have been illegally purchased in Pennsylvania and were confiscated by law enforcement.

Gawrysiak was arrested on charges of Unlawful Possession of a Weapon, Possession of an Assault Firearm, and Possession of a Defaced Firearm. Other charges are also pending from Pennsylvania authorities. He was being held in the Camden County Jail Thursday night on $500,000 bail.

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