Federal investigators on Thursday scoured the home of the 23-year-old man they say was behind this month's deadly Texas bombing spree, seeking clues about what motivated Mark Conditt and whether anyone helped him build or plant his bombs.
Police say Conditt, an unemployed man from the Austin suburb of Pflugerville, confessed to a three-week string of bombings in a 25-minute video made on his cellphone hours before he blew himself up as police closed in on him Wednesday.
"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.
"We're really working to make sure that that wasn't the case."
The bombs, which killed two people and wounded five others, primarily targeted Austin, the Texas capital and a fast-growing city of 1 million people.
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.
The attacks drew national attention when the second and third bombs went off while the city 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 and a former counterterrorism agent with the US State Department, said.
Austin's police department was unlikely to make the video public while the investigation continued, said spokeswoman Destiny Wilson.
Investigators sought further clues from the home Conditt shared with two roommates in Pflugerville, within walking distance of his parents' house.
Conditt and his three siblings had been 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.
"No form of education, public or private, can ensure a tragedy like this will never happen," Texas Home School Association President Tim Lambert said.
The Austin Stone Community Church, responding to reports that Conditt had attended, said in a statement late on Wednesday that it had no records of him being actively engaged with the church.
