Larry Grathwohl – an FBI informant known for infiltrating Bill Ayers and Bernardine Dohrn's radical Weatherman Underground Organization from 1969 to 1970 – was found dead in his Cincinnati apartment Thursday.

Grathwohl, 67, spent many years risking his life and attempting to ensure the group of traitors, cop killers and domestic terrorists were brought to justice.

The Weather Underground, an FBI-designated "domestic terrorist group" that sought to topple the U.S. government, notoriously bombed banks, federal buildings and police stations – even killing a police officer and injuring others. Members provoked riots, organized jail breaks, committed arson and conspired with communist regimes in what they saw as a violent revolution for social justice and peace that would bring into power a totalitarian communist dictatorship.

The Weather Underground reportedly planned to bomb airplanes and assassinate the president, vice president, attorney general and New York Gov. Nelson Rockefeller.

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The group even intended to murder one-tenth of the U.S. population, labeling them "diehard capitalists," and to put many more into "re-education" camps in the Southwest.

Grathwohl, author of "Bringing Down America," infiltrated the group while it plotted to blow up police stations and a power plant.

After serving in the U.S. Army as a paratrooper in a Hatchet Force unit of the 101st Airborne Division, Grathwohl came home from Vietnam in 1966 and became a drill instructor at Fort Knox, Ky. During his 13-month tour, his unit received two Presidential Unit Citations, a Meritorious Unit Citation, Valorous Unit Award, Republic of Vietnam Gallantry Cross with Palm Unit Citation and other medals, including a Bronze Star with a V.

In 1968, Grathwohl attended the University of Cincinnati and was recruited the following year by the Weatherman faction of the Students for a Democratic Society on the university campus.

"I immediately went to the Cincinnati police department, [which] asked me to attend the meetings that I had been invited to," Grathwohl told The Blaze in an April 8 interview with Andrew Wilkow. "Later, after the national action which occurred in Chicago in October of 1969, I went to the FBI, realizing that this was a national organization, not a group of nuts that were confined necessarily to Ohio or Cincinnati."

He said members of the group "actually believed that they were capable of overthrowing the government."

"[T]here was a lot of turmoil in the country, both anti-war movements and also a big uprising with civil rights," he said. "So it was kind of easy for these guys to think that maybe they were part of an international conspiracy that was going to overthrow the government. They honestly believed that they were going to succeed and that the only way to accomplish this goal of creating a communist society and government here in the United States was by strategic sabotage."

Grathwohl explained that members divided themselves into groups of four to five people who operated in cities throughout the United States until the mid-1980s.

Asked why the Weather Underground selected him to be in the organization, Grathwohl said he had told the leaders he was disillusioned with his experience in Vietnam.

He added, "But it just so happens that at the very time they attempted to recruit me, in the spring of 1969, they had been to Cuba, where they had been in meetings with the North Vietnamese and the Cubans, and they were criticized for being an elitist group – mostly upper-middle-class or upper-class backgrounds, well educated – and that they needed to be looking for recruits who had military experience and were street wise, working-class people. And here I came."

Grathwohl had his cover blown when police arrested radical leftist and Weatherman leader Linda Evans in April 1969. The FBI used his testimony to prosecute Evans.

He said after the organization went underground, it had purged everyone it considered "politically weak."

"The people that were left were people like Bill Ayers, Mark Rudd, Bernadine Dohrn, who were certainly committed – at least in one another's eyes – to this revolution and to this strategic sabotage."

In 1974, Grathwohl testified before the U.S. Senate, identifying Dohrn as the person who spearheaded a deadly bombing.

Grathwohl said it's "ludicrous" that so many leaders in the Weather Underground went on to teach at major universities.

"I told my mom the other day, I said, 'You know, the problem for me is that I didn't become a criminal. I should have [gone] out and robbed a Brinks armored car and killed two cops and a guard, and today I'd be a professor at Columbia University and also an associate or adjunct at the New York University Law School. … It's like the bad guys are the good guys, and the good guys are the bad guys.

In the years before his death, Grathwohl often traveled to seminars where Ayers and Dohrn spoke to call them to task for their terrorist acts of murder.

In April, he wrote, "I have spent years attempting to warn fellow Americans of the dangers these people pose now, as well as they did in the past. Bill Ayers and Bernadine Dohrn have not changed the color of their stripes and they continue – to this day – to destroy this country's government and [their plans] replace it with communism."

Upon word of his death, PJ Media called Grathwohl "one of America's truly unsung heroes," adding:

"Larry dedicated the better part of his life to seeing these despicable traitors brought to the justice they so richly deserve, and he paid heavily for it. It is a sad day in America when such a true hero dies in obscurity, while one of our very worst is feted in the cocktail circuit, lives high on the hog as a parasite on America’s back, and spends his every waking moment trying to destroy the country that could produce such men as Larry. …

"If there is any justice, Ayers and Dohrn will ultimately reward Larry's sacrifices by facing prosecution for their crimes in this world. Either way, they will certainly face a horrible reckoning in the next.

"Goodbye Larry; friend, compatriot, hero. America is a smaller place today."

Just months before his death, Grathwohl issued an ominous warning about those who seek to destroy America.

He told Sher Zieve of the Canada Free Press, "Today the same goal is being pursued with a certain amount of success through the means of the political process; which has manifested itself in the form of Barack Obama and his administration. Simply take note of the numerous attacks on the Articles of the Constitution and the resultant attempts on the part of Obama's government to deprive us of the liberties guaranteed by the founding fathers. These are liberties that are now being attacked, usurped and with every means possible destroyed and eliminated from the human rights upon which this country was established.

"Barack has not limited himself to merely attacking those liberties which he finds trivial but to include the very guarantee of freedom of speech by attacking any and all who oppose him. It is also important to note that Barack Obama is, without doubt, an associate, friend and fellow traveler along with Bernadine Dorn, Bill Ayers and many others who believe in the total destruction of this country."