Federal investigators are combing through the home of the 23-year-old they say was behind this month's deadly Texas bombing spree, seeking clues about what motivated his attacks the day after he killed himself in a confrontation with police.
Mark Conditt, an unemployed man from the Austin suburb of Pflugerville, confessed to the three-week string of bombings in a 25-minute video found on his mobile phone, police said.
Conditt blew himself up with one of his own bombs on Wednesday as police closed in on him in his car.
The bombs, which killed two people and wounded five others, primarily targeted Austin, the Texas capital and a fast-growing city of a million people. Three were left as parcels outside victims' homes, one by a footpath 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 video showed a troubled young man, according to Austin Police Chief Brian Manley, but did not outline a clear motive for the attacks that began March 2.
The 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 moved into last year and shared with two roommates in Pflugerville, which is within walking distance of his family's house. Agents from the Federal Bureau of Investigation and the Bureau of Alcohol, Tobacco, Firearms and Explosives are helping Austin police.
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.
"Raised by both parents in a Christian home, Conditt reportedly walked away from his faith several years ago," Texas Home School Association president Tim Lambert said in a statement late on Wednesday.
"Unfortunately, no form of education, public or private, can ensure a tragedy like this will never happen."
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.
Five of Conditt's bombs exploded, one was recovered before it went off, and the seventh Conditt detonated as officers rushed his vehicle.