Within a week we've seen examples of homegrown terrorism in two parts of the world. The first, in Norway a week ago, ended in the massacre of 76 people; the second occurred in Texas, where an alleged plot was foiled thanks to a concerned gun shop owner.

The randomness of these cases shows that no city or town in the civilized world is immune to acts of individual terrorism. The lone wolf is often the most difficult for law enforcement agencies to trace.

These latest cases show just how critical average citizens have become as a line of defense for their communities. In Norway, the warnings signs were missed while in Texas, an alert was sounded, avoiding a catastrophe.

An alert gun shop clerk named Greg Ebert led to this week's arrest of Nasser Jason Abdo, a AWOL soldier. Abdo appeared to be preparing for an attack on the army base at Fort Hood, Texas, as well as the city of Killeen, because of his anger against the wars in Afghanistan and Iraq.

Ebert, who retired last year after spending 17 years with the Killeen police force, works in the same gun store where Army psychiatrist Maj. Nidal Hasan bought a pistol which he used in a killing rampage at Fort Hood two years ago. Hasan faces a possible death sentence on 13 counts of premeditated murder and 32 counts of attempted premeditated murder when he goes on trial next year.

In this week's case, Ebert's suspicion was aroused Tuesday after Abdo reportedly arrived at the store by taxi and bought six pounds of smokeless gunpowder, three boxes of shotgun ammunition and a magazine for a semi-automatic pistol.

What raised Ebert's suspicion was the Abdo's nervous demeanor and his probing questions, including "What is smokeless powder?" The fact that Abdo first purchased six pounds of explosives before asking what it was raised a red flag in Ebert's mind.

"(We) felt uncomfortable with his overall demeanor and the fact he didn't know what the hell he was buying," Ebert said. "I thought it prudent to contact the local authorities."

That prudence likely helped avert a potential massacre. Law enforcement officials later found a cache of arms, explosives and bomb-making components at the suspect's hotel.

There is no indication that Abdo, who applied for conscientious objector status last year, was working with others. Like the deranged Norwegian gunman, he is being considered a home grown terrorist who was working alone.

These lone wolves are the hardest to detect and the reason why average Americans – concerned citizens like store clerk Greg Ebert – will unknowingly find themselves on the front lines in the war against terrorism.

By Jim Zbick

jzbick@tnonline.com