"...law enforcement source..." - Who? Cite your source, or it's invalid.

"...of a suspicious car..." - How was the car suspicious?

"...was carrying a notebook that contained the phrases, 'al Qaeda', 'Taliban rules', and 'Mujahid defeated croatian forces.'..." - Oh dear.. a notebook? With words? What is this world coming to?! Arghhh *insert wilhelm scream*!!

"...Despite the references to the terror organization..." - Reporters, cops, students, etc. write down references to these organizations all the time too. Does that make them suspicious? And 'despite'.. what the hell does that mean? Bias author. Bias. Learn how to write in a neutral tone.

"...references to the terror organization that organized the 9/11 attacks..." - What does 9/11 have to do with this guy? Irrelevant. Do not include irrelevant trivia in proper news articles.

"...the source said the man is not thought to have been involved in a terrorist act or plot..." - Then why is he a suspect? Don't you need a crime before you can have a suspect?

"...the man's backpack also contained 20 spent 9 mm shell casings..." - Oh dear. Spent casings.. good thing they can't be used in a shooting crime now. Good thing us lowly citizens are not allowed to defend ourselves. Or even practice with the weapons. You know 'practice', so we shoot only the bad guys stealing our women (and not other fellow citizens).

"... and three cans of black spray paint..." - Black spray paint? Oh no! What is this world coming to?! Arghhhhh *insert another wilhelm scream* Wait, only 3 cans? Newbie. :P

"... a non-explosive material was also found..." - Non-explosive? Then why mention the word explosive? Oh yah.. for the shock/terror effect. I too, btw, also found some non-explosive material in my backpack. That reminds me, I need to wash my blankie.

"...A law enforcement official speaking on the condition of anonymity..." - Yah, good ol' reliable anonymous source. These anonymous sources always work so well to support unsubstantiated and biased information.

"...officials found what appeared to be an unknown quantity of ammonium nitrate..." - What officials? "Appears to be".. don't they have any chemical analysts on staff? "Unknown quantity"? Sigh. Morons. Always talking crap about crap they don't know crap about. Don't release guesses in a news article!

"...The official, who was not authorized to release the information..." - Speaks for itself.

"...nothing else was found that would have enabled an explosion..." - What, not even any beans? What is the author's obsession with there being an explosion at the Pentagon? It's like he wants it to happen...

"...Ammonium nitrate is a chemical compound that is widely used in fertilizers..." - Actually, it is NOT widely used. AFAIK, around 5% of all fertilizers sold. Again, irrelevant bias.

"...and can be used in explosives with the correct concentration..." - Um, so can sugar. And flour. <badlogic>Arrest all the bakers!</badlogic>

"...The man...was being held by the U.S. Park Police. No charges have been filed against him." - Then why is he being held?! What the hell.

"...The man was detained after the U.S. Park Police came across him in early Friday morning in Arlington National Cemetery..." - Got it. Don't be in a cemetery on Friday mornings.

"...The Park Police then launched a search for the man's vehicle, which was found near the Pentagon..." - What prompted a search for his vehicle? Are they confusing cause and effect?

"...The 2011 red Nissan..." - Aha, now we are getting somewhere. A teenager has an expensive new vehicle.. surely trouble follows, eh?

"... including the use of a water cannon..." - Bet they showed him! Asshats probably destroyed his brand new car.

"...no suspicious items were found in the vehicle..." - Well, of course not. They were blown out by the water cannon!

"...suspected of planting suspicious devices..." - What? What devices? Is this anything like the 'college student brings fake bomb to airport' scandal? You know, the piece of art that was not anything like a bomb. Nor declared or nor described as a bomb?