Piatek, 46, was taken into custody Sunday in suburban Clarendon Hills. He lives in Whiting, Ind., and is one of 9 people connected to a Christian militia group based in Michigan that allegedly planned to kill a police officer and then attack other officials attending his or her funeral.
All nine suspects- including Piatek, are charged with conspiring to kill police officers. U. S. Attorney General Eric Holder called the arrests "a severe blow to a dangerous organization."
Seven members of the militia group Hutaree were arraigned Monday. One of them is considered a fugitive.
"Appear to be very much animated by not merely beliefs about the kind of new world order and the takeover of the world by evil forces but had a very particular Christian kind of interpretation of this," said Mark Potok, Southern Poverty Law Center.
The raids, including the one on Piatek's northwest Indiana home, were carried out over the weekends. His neighbors said they had no idea the man who always dressed in camouflage was allegedly involved in a radical Michigan-based militia group.
He was known as the neighbor with German shepherds and lived in a cluttered brick Whiting, Ind., 2-flat that he owns with his brother. They kept to themselves, neighbors said.
"I see him out there playing with his dogs. They walk up and down the street, but other than they seem nice," said Laurie Yager, neighbor.
"We would just say hi and nice dogs, kind of crazy. He trained them to actually hurt people, but they never bothered none of us," said Ron Jakuvczak, neighbor.
Dozens of law enforcement members who spent more than three hours searching Piatek's home on Saturday night.
"I saw squad team members out in the yard and police everywhere and cars blocking off roads. Bomb squads with shields and everything," said George Ponce, saw raid.
Neighbors said FBI agents hauled away several boxes of evidence, including dozens of guns. Piateck was not home, but the FBI caught up with him at a friend's apartment in suburban Clarendon Hills, where his pickup truck is still parked.
On Monday morning, Piatek appeared before a federal magistrate. He and eight others with the Christian militia group Hutaree are charged with a plot to kill police officers. Speaking in court and appearing confused, Piateck told the judge, "What is alleged against me and what I have done are two different things"
Piatek was wearing a polo shirt-- not the Army fatigues neighbors say Piateck usually wears.
"The whole 9 yards with the camouflage and military boots," said Jakuvczak.
Co-workers at a South Side steel drum company where Piateck worked as a $20 an hour truck driver said he always wore camouflage. No one at Meyer Industrial Container knew he was part of a militia group, but one employee said he was not surprised.
That employee also said he is not surprised about the charges against Pietek, but would not elaborate.
No one at Meyer Industrial Container would go on camera.
Piateck will return to federal court on Wednesday. Federal prosecutors say he is charged with an April plot to kill a police officer and attack more members of law enforcement at the officer's funeral.