Undercover Agent Key Witness Against Hutaree Militia Members

The undercover agent credited with infiltrating a Christian extremist group before it could carry out its alleged plot to kill law enforcement officers has provided potentially damning evidence that Hutaree leaders were planning a "new revolution."

The undercover agent's time with the Hutaree, a Michigan-based militia group with extreme anti-government views, appears to be at the heart of the case against nine members, including the Hutaree leader, David Stone, his wife and two sons.

VIDEO: An FBI agent risked his life to infiltrate a radical Christian militia group.Play
FBI Went Undercover With Hutaree

Among the evidence is an audiotape in which Stone allegedly said, "Welcome to the new revolution."

Revelations about evidence against the Hutaree came during the arraignment of eight of the nine members at a U.S. District Court in Detroit. They pleaded not guilty.

The suspects are due back in court today, where a judge is expected to rule on whether they will be granted bond.

The ninth member, Thomas Piatek, was ordered in an Indiana courtroom to be held without bond until he is transferred to Michigan to join the other defendants. He didn't enter a plea.

VIDEO: Nine members of the Hutaree are indicted by a federal grand jury. Play

The undercover federal agent described a sort of training day at Stone's home June 13, 2009, where members -- who describe themselves as "warriors" -- were shown improvised explosive devices, including one known as a "bouncing Betty," which is designed to kill several people at once.

The group was arrested in a multi-state raid Sunday. Court documents charge that the group had planned to kill an unidentified law enforcement officer, then target the officer's colleagues with IEDs and other explosives during the officer's funeral.

Former FBI agent David Gletty has infiltrated hate groups and said what that undercover agent did to expose the Hutaree was risky.

"To get in as deep as he did, for them to have federal search warrants and arrest warrants," he said, "this guy had to be in there for a while and he had, of course, to risk his life to get in with these suspects."

The agent reported that he also heard Stone allegedly tell his followers that they should train harder because war was coming and that he wanted to "own his own country."

Prosecutors have said Hutaree member Kristopher Sickles, one of the nine charged, killed his own cat so he could "see if he had it in him to kill something he cared about."

FBI officials said they've been tracking an increase in Web chatter from like-minded groups in recent days.

"I think what we are seeing out there is a real cauldron," Mark Potok of the Southern Law Poverty Center said, "a kind of witch's cauldron of fury over a whole set of issues that range from the changing demographics of this country, the election of a black president."

Prosecutors: Hutaree Built 'Hit List' of Federal Judges, Educational Leaders

According to prosecutors, Josh Stone -- David Stone's son, who was also arrested -- allegedly posted a declaration on a militia Web site that the Hutaree was ready "to go to war." Stone alleged in the posting that the Bureau of Alcohol, Tobacco, Firearms and Explosives, a federal government agency, wanted a "fire fight" with the group.

The Hutaree was divided into two teams that were being trained to kill law enforcement officials, according to Assistant U.S. Attorney Ronald Waterstreet. The group built a "hit list" of federal judges and educational leaders.

Waterstreet also played the courtroom an audio recording of David Stone, during which he says, "People around the world are waiting for people like Hutaree to go to war."

David Stone's lawyer William Swor said the recording demonstrated Stone has opinions.

Mark Satawa, the attorney for one of the accused, 40-year-old Michael David Meeks, said in a statement that his client "looks forward to being vindicated."

The Stone family has been at the center of the investigation since it began.

Those who have met the family describe them as socially awkward, a trait that some say as on display at the wedding earlier this month of Josh Stone.

The bride wore white, but the groom -- and all of his family, including the tyke who was the ring bearer -- wore camouflage combat uniforms.

"I was really surprised. It just seemed so inappropriate," Donna Spurgeon, the wife of the minister who directs the church where the March 13 wedding was held, told ABCNews.com. "She was a beautiful bride and had a beautiful white dress and it seemed really odd" next to the military garb.

Photographs were posted on a Facebook page that belongs to Karen Belcher. Belcher is a friend of the bride, Shannon Witt, and was asked to photograph the wedding. She said that most of the men at the ceremony were in full military fatigues.

Even a young ring bearer, who appears to be no more than 6 years old, was wearing the uniform.

"I knew [the Stones] were different, I just didn't know how different," said Belcher. "That was my first meeting."

Belcher said that Witt's family did not approve of the wedding, because they did not "like" the Stone family. Only Witt's mother, aunt and sister attended, according to Belcher.

"I think Shannon was pretty much brainwashed. She had no clue of what all what went on," said Belcher. "She's pretty innocent, naive. It was a shock to her like it was to the rest of us."

Belcher said the Stone family members were all very nice to her at the wedding, but that she didn't have lengthy conversations with any of them.

Spurgeon, whose husband is the pastor of the Thornhill Baptist Church, said the Stones preferred that a "chaplain from their group" officiate at the wedding.

She said that about 40 people attended the wedding and reception, and that at least 15 were wearing military uniforms.

"I was surprised," said Spurgeon of the whole ordeal. "But the bride looked very happy."

Members of Hutaree Were Home Schooled

The Stone family attended the Thornhill Baptist Church "about once every three months," according to Spurgeon, but were always polite and well behaved when they did show up. Spurgeon said that her church did not condone anything the Stone's are said to believe in. "That's not the teaching that they got at our church," Spurgeon said.

Josh Stone and David Stone Jr. were both home schooled and seemed to lack friends their own age, according to Spurgeon.

"They needed to be exposed to kids their own age," she said. "But they were not wild children at all. They were very polite, very respectful and very kind."

The parents, David Stone Sr. and his wife, Tina, were always very polite, although he always seemed like he had drank too much coffee," said Spurgeon.

"David just always seemed really hyper, like, calm down," said Spurgeon.

Despite their personalities and the military garb, Spurgeon said she never suspected anything out of the ordinary. She figured that the men in the family, like many in the rural town of Clayton, Mich., just enjoyed hunting.

"I thought they were a bunch of guys who liked to go hunting together and dress in military garb," she said. "We heard them talk about getting the deer and that type of thing, but I never knew it had any military connotation or a connection to law enforcement. ... I certainly had no idea."

ABC News' Sarah Netter and The Associated Press contributed to this report.