NEW ORLEANS, LA (WVUE) - Police now say a serial bomber is responsible for a fourth explosion in Austin, Texas. The latest bomb has police especially concerned because it was triggered by a trip wire.
We spoke with a local security expert who says he's very concerned by the bomber's apparent level of expertise.
In the four bombings in Austin just this month, two people have been killed and four others injured.
"That's been the question all along - is this terrorism, is this hate related? And we're early on in this investigation today. We've got into the preliminary phases, and as the day moves on, that is something we're going to analyze. We're clearly dealing with what we expect to be a serial bomber on this point based on the similarities between now what is the fourth device," said Austin Police Chief Brian Manley.
The first three bombs were inside packages and left on doorsteps, but the latest device was left on the side of the road and was triggered by a trip wire. Unlike the previous explosions, the latest victims were two white men.
"Totally random, totally indiscriminate. That's the scary part," said Robert Allen, a Tulane University professor of domestic and international terrorism.
Allen says he's very concerned by what's happening in Austin.
"This is extremely dangerous. I think this guy, I don't think he's impulsive, but I think he is very methodical, I think he's very intelligent i.e. Ted Kacinski, the Unabomber. He's not dumb in any sense of the word," said Allen.
Austin's police chief says because the latest device was triggered by a trip wire, it shows a higher level of sophistication and skill.
"The incident last night concerned me immensely because it's totally indiscriminate - two people just walking along or riding their bikes or walking their bikes along over a trip wire, I mean that takes a little bit of sophistication right there," said Allen.
There's no motive yet, but the ATF is asking anyone in Austin who sees something suspicious to stay away from it. Agents say if they move a package or step on a trip wire, it's likely to explode.
"Again as we look at this individual and the pattern and what we're looking at here, we'll have to determine if we see a specific ideology behind this or something that will lead us along with our federal partners to make that decision," said Manley
A $115,000 reward is now being offered for information leading to an arrest.