To some of the people who know him back home in Texas, Brandon Darby is a traitor.

In his own mind, he's proud of what he did — feeding the FBI information that led to the arrests of two men accused of trying to disrupt the Republican National Convention.

"I feel like, as an activist, I played a direct role in stopping violence," Darby, 32, said in an interview with the St. Paul Pioneer Press.

Darby's role as a confidential informant in the case leaked out in a pretrial hearing. It was a remarkable transformation for a man known to many back in Austin as a fiery, grass-roots activist with a mistrust of government.

Darby was key to the investigation of David Guy McKay and Bradley Neal Crowder, both of Austin. The two men are scheduled for federal trial on Jan. 26 for allegedly building Molotov cocktails during the convention. They have pleaded not guilty.

Prosecutors claim the two men built the firebombs because they were angry that police had seized a trailer filled with riot shields they'd built and hauled to Minnesota. In a conversation recorded by the FBI, McKay allegedly told Darby he planned to use the explosives on law-enforcement cars parked in a lot near the Xcel Energy Center.

In an e-mail to friends this week, Darby said he was comfortable with what he had done, the Pioneer Press reported.

"Like many of you, I do my best to act in good conscience and to do what I believe to be most helpful to the world," he wrote. "Though my views on how to give of myself have changed substantially over the years, ultimately the motivations behind my choices remain the same."

His admission surprised Austin's activist community.

"Everyone that knew Brandon has gone through a whole range of emotions. Clearly, he's betrayed the trust of the community, and all the communities he's worked with," said Lisa Fithian, a social-justice activist who worked with Darby in Austin.

Darby grew up in Houston and became an emergency medical technician. He had plans to work abroad helping civilian victims in war-torn areas. But it was in New Orleans after Katrina that he made a name for himself as an activist by helping to start the Common Ground Collective, a network of nonprofits that delivered food, water and other aid.

"When I showed up in New Orleans, I was very angry at my government," Darby said. "I felt that rather than just protest what happened in New Orleans in your own city, it was important to protest by going to New Orleans and doing something about it."

But Darby said that while working on the Gulf Coast, he concluded that some activist organizations were more intent on radical agendas than actually helping people.

"Common Ground had over 22,000 volunteers, and the vast majority of those were average working-class Americans who just wanted to help," he said. "But what happens is, different political groups or people with ideologies show up and their focus is on their agenda. ... There was a lot of that going on."

After working in New Orleans, Darby returned to Texas. Court documents reveal he began working as an informant for a San Antonio FBI agent in November 2007, the Pioneer Press reported.

Darby said he did it because he discovered that people he knew were planning violence. "Some of them had really bad intentions," he said.

By February 2008, Darby was involved with a group of activists in Austin, some of whom were making plans to travel to St. Paul to demonstrate during the Republican National Convention.

According to FBI affidavits, Darby provided agents with information about meetings the group had as well as meetings with activists in other parts of the country, including a planning meeting in Minneapolis in May. He also purportedly provided information about riot shields McKay and Crowder had made from highway safety barrels. A rented U-Haul trailer held 35 of the shields as well as helmets and batons.

Affidavits and testimony in pretrial hearings show that Darby was providing FBI agents with updates on the location of the trailer. St. Paul police eventually found the trailer, broke the lock and seized its contents. A federal magistrate has recommended that the shields and other items be excluded from evidence at the upcoming trial because police never sought a warrant to search the trailer.

Darby told agents that McKay and Crowder decided to retaliate by building Molotov cocktails. They bought the materials at Wal-Mart on University Avenue in St. Paul, then built the devices and stored them at the Dayton Avenue apartment building where they were staying. Police later raided the building and seized eight firebombs in the basement.

After Darby's name leaked out, some colleagues were quick to dismiss the possibility he had been an informant. Scott Crow, a friend who worked with Darby to start Common Ground Collective, said it was "an absolute ... lie."

After getting Darby's e-mail this week, Crow said he was shocked. "I can only say it's heartbreaking and it's shocking. This is somebody who has been known to me for six years, and it's shaken me to my core that somebody this close to me had been informing on me and others," he said.

Darby said he's proud of the role he played, and he believes it helped make life more "stable."

"I decided that the way I was going about things was not the right way to do it," he said. "While it may have satisfied part of me, it really wasn't changing anything."