(CBS) - The man police say was behind a mass shooting in Washington, D.C. Monday was arrested in September 2010 for allegedly firing a gun inside his Texas apartment, reports the Ft. Worth Star-Telegram.
Police suspect Aaron Alexis, 34, shot and killed 12 people and wounded at least three others on Monday morning at the Washington Navy Yard. Alexis was also killed at the scene. A motive for the killings is not known.
According to the Star-Telegram, friends say Alexis was in the Navy from 2007-2011, but left because he didn't like waking up early. The Associated Press is reporting that Alexis was a former Navy reservist stationed in Ft. Worth.
The newspaper interviewed a man named Nutpisit Suthamtewakul, who described Alexis as his "best friend," and said he knew his former roommate had a gun but "didn't seem aggressive to me."
The Star-Telegram reports that the 2010 incident did not result in charges against Alexis, but that his landlord at the apartment where he was arrested began eviction proceedings against him and Alexis moved out in November of that year.
A more recent landlord told the Star-Telegram that Alexis liked to meditate, and other friends told the paper he had recently traveled to Thailand.
"I can't believe he would do anything like this," Somsak Srisan told the newspaper. "He always behaved well around me."
Customers at Happy Bowl Thai, a restaurant owned by Suthamtewakul, also told the paper that Alexis occasionally worked there as a waiter.
At a press conference Monday afternoon, the FBI urged anyone with information about Alexis to come forward, saying they were looking for any information regarding Alexis' recent movements, contacts and associates.
"No detail is too small," said Valerie Parlave, an assistant director in charge of the Washington FBI field office. "We will continue to run down every lead."