Army, FBI investigators search for motive behind deadly shooting rampage

Gallery

'Horrific outburst of violence'

An Army psychiatrist allegedly opened fire Thursday in a crowded medical building at Fort Hood, Tex., killing at least 13 people and wounding others.

» LAUNCH PHOTO GALLERY

Rossi said an investigation will determine how the shooter brought guns onto the post, where, like at all U.S. military installations, firearms are kept secured unless they are needed for training or security work. Soldiers and civilians are allowed to maintain privately owned weapons in accordance with local gun laws, Rossi said. But they must register those weapons on post.

Officials say they believe Hasan -- who reportedly lived off-post -- used his own personal handguns in the shooting. The military is trying to determine whether those guns were registered. Although "random checks" are performed on vehicles arriving at and departing from Fort Hood, Rossi said, soldiers aren't searched as they leave or enter the post.

Rossi said officials do not believe there were any additional people involved in planning or carrying out the rampage.

Asked if there were any other persons of interest in the shooting, Casey told reporters, "There is only one remaining suspect at this point." He did not elaborate.

Officials said they have not been able to interrogate Hasan -- a devout Muslim born to Palestinian immigrants and raised in Virginia -- because of his medical condition. They have not spoken to his relatives, either, Rossi said.

According to a federal sources, investigators seized Hasan's computer from his apartment in Killeen near Fort Hood and were performing routine tests on it. They were also looking into whether Hasan was the author of Internet postings about suicide bombings and other threats, including one that likened Islamic suicide bombers to U.S. soldiers who sacrifice their lives to save fellow soldiers and to Japanese kamikaze pilots during World War II.

Hasan was not the target of an existing law enforcement investigation but had come to the attention of authorities in part because of the Web postings, a federal source said.

The FBI dispatched an evidence response team to Texas, as well as its shooting reconstruction team and agents from San Antonio, Austin and Waco. The bureau's Washington field office has been interviewing Hasan's colleagues, neighbors and other contacts in the Washington area, and other agents were sent to Virginia Tech, Hasan's alma mater.

Authorities said they were far from establishing a motive and suggested that it could take some time, because they must track down all the witnesses to the shooting and confront possible challenges related to doctor-patient confidentiality and privacy rights. It will be a "methodical" investigation, a federal source said.

Colleagues and relatives have said Hasan opposed the wars in Iraq and Afghanistan and was upset about his looming deployment.

According to a classmate at the Uniformed Services University of the Health Sciences in Bethesda, where Hasan studied last year, he viewed the war on terrorism as "a war against Islam," the Associated Press reported. The agency quoted the classmate, Val Finnell, as saying Hasan told classmates he was "a Muslim first and an American second."

At the apartment complex where Hasan lived in Killeen, manager John Thompson said another soldier vandalized Hasan's car and tore off a bumper sticker that read "Allah is Love," prompting Hasan to file a complaint to police. The soldier had been in Iraq and was upset to learn that Hasan was Muslim, Thompson told the AP.