One of the largest bombing investigations in the U.S. since the Boston Marathon attacks in 2013 came to an intense close early Wednesday when authorities say they moved in on Mark Anthony Conditt at an interstate hotel. Austin Police Chief Brian Manley said Conditt blew himself up after running his sport utility vehicle into a ditch.
Here is what's known about how authorities finally zeroed in on the suspected bomber after 19 days, two dead victims and more than 1,000 calls of suspicious packages around the city:
GETTING THE BOMBER ON CAMERA
Conditt had been careful to avoid cameras before entering a FedEx store in southwest Austin this week disguised in a blond wig and gloves, said U.S. House Homeland Security chairman Michael McCaul. The Austin congressman had been briefed by police, the FBI and the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives.
McCaul said going into the store was Conditt's "fatal mistake." He said authorities previously had leads on a red truck and that the surveillance video from the FedEx store - where Conditt is believed to have dropped off an explosive package destined for an Austin address - allowed investigators to identify him and the truck.
Said Texas Gov. Greg Abbott, "I'm not sure how much they narrowed him down to an exact person of who he was before he went into that FedEx store."
TRACKING THE CELLPHONE
At the FedEx store, McCaul said investigators got from surveillance the truck license plate that linked the vehicle to Conditt, which in turn gave authorities a cellphone number they could track. McCaul said Conditt had powered down his phone for "quite some time" but that police closed in when he switched it back on.
"He turned it on, it pinged, and then the chased ensued," McCaul said.
Abbott said police were able to closely monitor Conditt and his movements for about 24 hours before his death. The governor said the phone number was used to tie Conditt to bombing sites around Austin.
"The suspect's cellphone number showed up at each of the bombing sites as well as some key locations that helped them connect him to the crime," Abbott said.
BUYING BOMB-MAKING MATERIALS
Authorities say they also tracked down Conditt, a 23-year-old unemployed college dropout, through witness accounts and other purchases, including at a Home Depot where McCaul said the suspect bought nails and other bomb-making materials.
Abbott said Conditt's purchases at the Home Depot also included five "CHILDREN AT PLAY" signs, one of which was used to rig a tripwire that was set off by two men Sunday in a southwest Austin neighborhood. One of them was walking and the other was riding a bike.
William Grote told The Associated Press that his grandson was one of the victims and had nails embedded in his legs from Sunday's explosion.
The batteries to power the bomb were purchased through the internet, McCaul said.
STILL PUTTING TOGETHER A PROFILE
The initial bomber profile sketched out by FBI behavioral scientists was that he was most likely a white male, McCaul said. And while that part was right, the congressman said, a full psychological profile won't come together until investigators have time to comb through Conditt's writings and social media posts.
Conditt's motive is not clear. But on Wednesday, police discovered a 25-minute video recording on a cellphone found with Conditt, which Manley said he considers a "confession" to the bombings. Manley said it described the differences among the bombs in great detail.
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