Talk about a tough crowd. When former Islamic militant Aukai Collins stood before 150 or so local law-enforcement personnel on Monday and proceeded to label John Walker Lindh a " coward " for hiding in the basement at Mazar-e-Sharif instead of fighting to the death, you could have heard a pin drop — or, for that matter, a safety catch go off. But it wasn’t the fact that many in the audience were armed (and less than sympathetic to the principles of jihad) that unnerved Collins. " Erm, er, uh, " the one-time holy warrior began, before sputtering a series of You knows and It’s sort of likes.

The American-born Collins, who recently published a very bracing memoir called My Jihad: The True Story of an American Mujahid’s Amazing Journey from Usama bin Laden’s Training Camps to Counterterrorism with the FBI and CIA (Lyons Press), may have rubbed rocket launchers with the tribesmen of Pakistan, undergone a grueling training regimen in the camps of Afghanistan, and had his right leg blown off on the battlefields of Chechnya, but public speaking was clearly getting the better of him. By the time the Q&A session started, the 28-year-old warrior was puffing his cheeks and letting his responses trail off into nothingness. " It’s just ... you can’t ... oh, I don’t know ... "

Nonetheless, Collins was one of the highlights of a two-day conference on terrorism, conducted by the Virginia-based Terrorist Research Center (TRC). The conference, held in the austere the environs of the MBTA Police Training Academy in Quincy, covered such topics as " [A] Comparative Look at the Mindset of Terrorists " and " Chem/bio Threats and Response. " Collins’s speech — " Terrorist Tactics and Training " — was supposed to give insight into the kinds of things terrorists do when preparing to create havoc.

" None of us has trained at a camp in Afghanistan, " explained the TRC’s director Walter Purdy before the speech. " None of us has sat around the campfire with Omar Saeed Sheikh [the alleged kidnapper of slain Wall Street Journal reporter Daniel Pearl]. "

Originally from San Diego, Aukai Collins converted to Islam while serving time in a youth-detention facility, and subsequently spent a good deal of the ’90s traipsing around Kosovo and Kashmir in search of a fight — ending up in Chechnya, where he battled alongside Islamic rebels against the Russian army. He eventually abandoned jihad, he says, when he became disillusioned with the practice of " killing civilians and stuff. "

Shaven-headed and sporting a long goatee, Collins looked more Limp Bizkit fan than mujahideen. Only a slight limp as he made his way to the podium gave any indication of his time spent in the midst of some of the planet’s bloodiest conflicts. As the lights went down, you got the distinct impression that Collins would rather fight a hundred hand-to-hand battles than stand before an audience to describe what combat is like.

An author photo of Collins, projected large on the wall behind him — automatic rifle in hand, his prosthetic leg resting jauntily on a railing — seemed a far cry from the wide-eyed man who knitted his hands and searched, often fruitlessly, for words to describe his wartime experiences. Indeed, if Collins gave us any insight at all, it was that fear often lurks in the strangest places. At one point, explaining how the Chechnyans preferred to engage the enemy at night, Collins paused, then added that his own inclination was to do battle during the day.

" I’m scared of the dark, " he said. " I’m not scared of soldiers, but monsters kind of get to me. "