(KILLEEN, Texas) -- When police searched the hotel room of the AWOL American soldier accused of planning a deadly bombing and shooting spree outside Fort Hood, Texas, between the firearms, ammunition and bomb-making materials, senior law enforcement officials said they also picked up a possible clue to the soldier's motivation -- an article from a jihadi magazine produced by al Qaeda.
The officials told ABC News Private First Class Naser Jason Abdo -- who had been granted conscientious objector status over his Muslim faith -- had apparently stashed in the room an article from the first issue of al Qaeda's Inspire magazine called "How to Build a Bomb in the Kitchen of Your Mom."
In addition to the magazine, one senior U.S. official told ABC News Abdo had also mentioned the name of one of the most high profile leaders of the Yemen-based al Qaeda in the Arabian Peninsula (AQAP), American-born Anwar al-Awlaki.
Abdo made his first appearance in court in Waco, Texas, on Friday where he was charged with the federal crime of possession of a non-registered firearm in addition to previous charges of possession of child pornography and going AWOL from his unit.
Al-Awlaki is considered by some U.S. security officials to be one of the most dangerous men in the world because of his ability to reach out through the Internet to so-called "lone wolf" jihadis who would attempt to carry out attacks on behalf of al Qaeda, but without any actual material support from the terror organization. Al-Awlaki is believed to have inspired several terror plots in the U.S., from the deadly 2009 massacre at Fort Hood and the bungled Christmas Day airline bombing.
AQAP, a media-savvy affiliate of al Qaeda, has produced six issues of Inspire so far, each featuring praise for martyrs and instructional sections on firearms and explosives for the prospective terrorist.
Abdo, a Muslim soldier who's in the 101st Airborne Division at Fort Campbell in Kentucky, attempted to leave the military in 2010 after protesting the U.S.'s involvement in Iraq and Afghanistan.
In August 2010, he told ABC News he should not have to participate in what he called an "unjust war".
"Any Muslim who knows his religion or maybe takes into account what his religion says can find out very clearly why he should not participate in the U.S. military," Abdo said then.
Days after the Army approved Pfc. Abdo's conscientious objector discharge, his release was put on hold and he was charged with having child pornography on his government-issued computer. Military investigators had been looking at Abdo's computer files after he made "radical statements," law enforcement sources told ABC News.
After he was told he would face a court martial, Abdo went AWOL from Fort Campbell on July 4. Though vocal in his protestations against the mission in the Middle East, Abdo did not make any public threats against the military.
But when he was discovered Wednesday, Abdo was apparently in the final planning stages of a deadly attack. He was caught in part because a wary local gun store owner called police after Abdo visited the store to buy ammunition and gunpowder. He was acting "suspicious," Guns Galore owner Greg Ebert told ABC News.
"There was clearly something wrong with him," Ebert said. "We made a decision to call the police and fortunately it worked out."
After his arrest, Abdo admitted he planned to plant two bombs at a local restaurant frequented by Fort Hood soldiers and hoped to gun down any survivors of the dual blast, according to law enforcement documents obtained by ABC News.
According to the documents, military officials believe the incident "was likely isolated to the Fort Hood area and the suspect in custody, and that arrest of the suspect has mitigated any further threats related to this incident."
Abdo's former lawyer, James M. Branum, declined to comment for an ABC News report except to say on Thursday that he hasn't spoken with his client "in a long time." Abdo now faces federal charges in connection with the alleged plot.
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