AUSTIN, Texas (Reuters) - Two roommates of the 23-year-old man behind this month’s deadly bombing spree that unnerved Austin have been questioned and released from custody, police in the Texas capital said on Thursday.
The move came as law enforcement officials searched for what motivated Mark Conditt, an unemployed man from the Austin suburb of Pflugerville, to commit the attacks that killed two people. Authorities are also anxious to learn whether anyone helped him build or plant his bombs.
Police say Conditt confessed to a three-week string of bombings in a 25-minute video made on his cellphone hours before he blew himself up, as law enforcement closed in on him Wednesday.
One of the two roommates was questioned and released on Wednesday and the other released after that. Police did not say exactly when the second roommate was freed.
“Their names will not be released because they are not under arrest at this time,” the department said on its Twitter feed.
Conditt’s bombs, which also injured five people, primarily targeted Austin. Three were left as parcels outside victims’ homes, one by a sidewalk with a trip-wire mechanism attached and two shipped as FedEx parcels, which helped investigators unmask the bomber’s identity.
“Even though the bomber’s dead, our focus is to ensure that he wasn’t working with anyone else,” said Michelle Lee, a spokeswoman for the Federal Bureau of Investigation’s San Antonio office.
The second and third bombs went off while Austin was hosting its annual South by Southwest music, movies and tech festival, which draws about half a million people.
The confession video showed a troubled young man, police said, but did not outline a clear motive for the attacks that began March 2.
“We may never get a clear picture of what motivated the Austin bomber,” Fred Burton, chief security officer for security consultancy Stratfor, said in a phone interview.
Austin police were unlikely to make the video public while the investigation continued, said spokeswoman Destiny Wilson.
Investigators sought further clues on Thursday from the Pflugerville home Conditt shared with his roommates. Bomb-making material was found in a room there.
Conditt and his three siblings were home-schooled through high school, his mother wrote on Facebook. He attended classes at Austin Community College between 2010 and 2012, but did not graduate.
Reporting by Jon Herskovitz; Additional reporting by Steve Gorman in Los Angeles and Jonathan Allen in New York; editing by Jonathan Oatis and Tom Brown