With federal authorities now investigating the recent assassination of Dr. George Tiller, an abortion provider in Kansas, new information is emerging about ties between the anti-abortion activist charged with the crime and extremist groups.

This weekend the Kansas City Star reported that suspect Scott Roeder was affiliated with the Embassy of Heaven Church, which the Southern Poverty Law Center describes as a "sovereign citizens" group that sells fake passports and other documents to its members, who do not recognize the authority of the U.S. government.

Based on filings from Roeder's divorce, the paper reported that the leader of the so-called church -- the former Craig Fleshman, who now goes by the name "Paul Revere" -- wrote letters to court officials in 1999 offering to pay child support owed by Roeder:

"We have faithfully informed the district court trustee that Scott P. Roeder is on assignment for us in the mission field and that we are handling his affairs," Revere wrote in an Aug. 10, 1999, letter.

Lindsey Roeder told the paper that she informed the FBI about her ex-husband's connection to the Embassy of Heaven, whose literature she reportedly hid from him because he wanted to send them their car title.

"Revere" said his group did not condone Tiller's killing, adding that killing anyone was a violation of its law.

The Embassy of Heaven Church is based in Oregon, but it has adherents from across the country including the South who have tried to use their status as members to legitimize tax evasion and other crimes. They include:

* John Joe Gray, wanted for allegedly assaulting a Texas state trooper in 1999, holed up on his farm 50 miles southeast of Dallas with the help of anti-government groups. The year before the incident, Gray signed a so-called "expatriation statement" from the Embassy of Heaven Church, renouncing his allegiance to all states and becoming a "citizen of the Kingdom of Heaven." He also received a "Heaven" driver's license, registration, vehicle titles, and license plates from the Embassy of Heaven, the group reports.

* Louis Genard of Slidell, La. was convicted of tax evasion in 2007 after a 12-year battle with the IRS. At a pre-trial hearing in the case, the dentist filed a motion claiming he was an "ambassador and citizen of the Kingdom of Heaven under its King Jesus the Christ," according to the SPLC.

* Embassy of Heaven member Frank Lewis of Anderson, S.C. staged a week-long hunger strike in 1997 when he was arrested for driving without a license and operating an uninsured vehicle. It was one of many hunger strikes staged by arrested members of the group, according to the Anti-Defamation League.

Dr. Tiller's May 31 murder was one in a series of recent incidents involving violence by political extremists.

On June 1, an attack on a military recruiting office in Little Rock, Ark. killed Army Pvt. William Long and injured Pvt. Quinton Ezeagwula. Arrested in that case was Abdulhakim Mujahid Muhammad, a Tennessee native and convert to Islam who has said the killing was justified by U.S. military action in the Middle East.

In 2007, Muhammad reportedly left Tennessee State University in Nashville where he was studying business and traveled to Yemen to teach English. Arrested for a minor visa violation, he was sent to a Yemeni prison where he was reportedly held with radical Islamists and questioned by the FBI.

And last week, an attack on the Holocaust Memorial Museum in Washington, D.C. by white supremacist and Holocaust denier James von Brunn resulted in the death of African-American security guard Stephen Tyrone Johns.

So far, Muhammad is the only one of the three suspects who faces any terror-related charges: 16 counts of engaging in a terrorist act by firing into an occupied building.