The FBI has closed its case on the Austin mail bomber who terrorized the Texas city last year, but agents were not able to deduce a motive behind the five explosions, which killed two people and injured at least five.
KXAN Austin reports that the FBI closed its case on the bomber on January 10th, nearly a year after the bomber blew himself up using one of his own packages. The Bureau has remained largely secretive about the case, releasing only a handful of details to the public over the course of the investigation.
"Since [the bomber's] death, federal agents have scoured every element of his life. Investigators interviewed [the bomber's] family, friends, neighbors and executed nine separate search warrants on his home, vehicles, electronic devices, financial records and on his digital life in an effort to figure out whether he acted alone," KXAN reports.
But even after almost a year sifting through the bomber's personal belongings and interviewing witnesses, the FBI was unable to come up with a concrete motive. The bomber did not ascribe to any particular ideology, nor did he belong to any fringe political groups, right- or left-wing. He had no ties to either domestic or international terror groups.
"In the course of its investigation, the Government found no evidence of communications or links between [the bomber] and any international terror groups or domestic hate groups," the final FBI filing read. "The Government likewise found no evidence that any recognized ideology had motivated [the bomber]."
The bomber did release a 25 minute "manifesto"-style confession right before he took his own life, detonating a sixth mail bomb on a highway near Round Rock, Texas, but the confession, CNN reports, was more like a litany of troubles than a clue as to why the bomber sent five packages to five homes across Austin, largely to minority families living in East Austin.
"It is the outcry of a very challenged young man talking about challenges in his life that led him to this point," one law enforcement officer told media. "I know everybody is interested in a motive and understanding why. And we're never going to be able to put a (rationale) behind these acts."
Law enforcement were able to lay out a better timeline of the bomber's reign of terror, tracking him across Austin using video surveillance equipment from Fed Ex stores where he shipped the bombs. In total, the bomber sent five bombs, four of which exploded at their intended targets, and one of which was intercepted at a Fed Ex facility near San Antonio.
Surveillance video from a FedEx drop-off location provided authorities with details about the suspect's vehicle including his license plate number. Authorities then tracked the bomber to a hotel in Round Rock, Texas, near where he mailed his last bombs. Before he could be apprehended by police, the bomber set off one of his bombs inside his own SUV, killing himself and injuring a police officer.
Authorities say they tried to keep the investigation as quiet as possible so as to avoid tainting any possible leads, but while detectives were able to recover "destructive device-making equipment, fraudulent paper license plate tags, a wig similar in appearance to that seen in the FedEx footage, over 100 pounds of ammonium nitrate, and other materials that could be used to manufacture additional destructive devices," they were not able to uncover a motive.
Both state and federal authorities are expected to release further documents on the case.