Dennis Franks is a former FBI agent who says the bomber is acting on ego.
"He's calculating things and he's always thinking about his next two moves ahead," Franks said.
He's also hoping for maximum attention.
"They're more than likely a sociopath, for someone to do this without remorse, without regard to life," Franks said.
Ex-FBI agent: Austin bomber's profile may surprise investigators
If the package that exploded at the FedEx facility accidentally went off while in transit, Franks says that could cause the bomber to act out.
"If there's some question about their competency, they're going to increase what they're doing probably," Franks said.
FedEx officials say the same person responsible for sending the exploding package also sent a second package that was safely handed over to law enforcement.
Franks says that could be key for investigators.
There are plenty of theories from the public. He warns the person may not be who you suspect.
"Look at the Unabomber," Franks said. "Whoever would have thought a college professor would have been the culprit behind all of those?"
With the frequency of the explosions, many think the bomber could mess up soon.
"I tend to think at some point there's going to be a slip up or someone is going to have sufficient information to provide to lead us to the culprit," Franks said.
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