Authorities are investigating multiple trips the Chattanooga gunman took to the Middle East as they work to identify the motive behind Thursday's shooting that killed four Marines.
Mohammad Youssef Abdulazeez, 24, a Kuwaiti-born Chattanooga resident who was killed by police during his shooting rampage Thursday, traveled to Jordan in 2014 and may have also visited Yemen.
Sources close to the investigation told Fox News authorities are trying to determine whether Abdulazeez had any contact with extremists during his seven-month stay in Jordan. Abdulazeez is believed to have traveled to the Middle East between April and November 2014.
Federal authorities were looking into the possibility the shooting was an act of terrorism, but say there is no evidence yet that anyone else was involved -- or that the public is in any danger.
A federal law enforcement official said Friday that authorities were continuing a search of his computer, but had not found an extensive online presence and had not uncovered evidence suggesting he was directly inspired by the Islamic State.
The FBI is investigating two blog posts written on Monday to determine if Abdulazeez was behind them, including one that proclaimed that life is "short and bitter" and urged readers to "submit to Allah," the Wall Street Journal reported.
The National Counterterrorism Center said it is still reviewing its data holdings and watch lists and have so far found no positive hits for Abdulazeez, though it emphasized the review is ongoing.
At approximately 10:50 a.m. Thursday, the gunman opened fire from his silver Mustang convertible at a military recruitment center in a strip mall east of downtown Chattanooga, where one Marine was wounded. Authorities said the shooter then drove 7 miles to a Navy Operations Support Center, crashing his car through a security gate before opening fire on four Marines, killing them. A police officer and sailor were also wounded.
Officials have not said what weapons Abdulazeez used, and even the exact spelling of his first name was not clear: Federal authorities and records gave at least four variations. Residents in the quiet neighborhood where he is believed to have lived in a two-story home said they didn't know him or his family well.
Abdulazeez got an engineering degree from the University of Tennessee at Chattanooga in 2012 and worked as an intern a few years ago at the Tennessee Valley Authority, the federally owned utility that operates power plants and dams across the South. For the last three months, he had been working at Superior Essex Inc., which designs and makes wire and cable products.
In April, he was arrested on a drunken driving charge, and a mugshot showed him with a bushy beard. In earlier photos, he was clean-shaven.
Hussnain Javid said they graduated a few years apart from Red Bank High School in Chattanooga, where Abdulazeez was on the wrestling team and a popular student.
"He was very outgoing," said Javid, a 21-year-old senior at the University of Tennessee at Chattanooga. "Everyone knew of him."
Javid said he occasionally saw Abdulazeez at the Islamic Society of Greater Chattanooga, but the last time was roughly a year ago.
Fox News' Catherine Herridge and The Associated Press contributed to this report.