GARLAND (CBSDFW.COM) – It started with bombs in packages.

But there is fear now that just simply walking anywhere could trip the next explosion in Austin.

“They’ve gone from targeting a specific individual to ‘I just want to kill someone.’ That’s concerning,” said Clint McNear, a former Garland detective who now operates McNear Consulting.

McNear understands what police in Austin are going through right now.

Ten years ago when he was a detective at Garland Police, he helped catch a serial shooter who went on a violent spree, shooting at least six people.

“It amplifies the pressure on law enforcement to get something done,” said McNear.

The shift from a bomb triggered by motion to a tripwire shows sophistication, according to McNear.

“They’ve done it repeatedly without harming themselves, they’re displaying that they have some knowledge,” said McNear.

Having built and transported at least four bombs, McNear believes it is likely not someone who is learning as they go.

“My mind was racing this morning. Is it a former oil-field worker that’s extremely familiar with explosive devices?” questioned McNear. “Is it a former military EOD? Former fire/police officer that’s got training in bombs?”

McNear believes what won’t help stop the bomber is fear.

“I would beg the public to not panic, to be prepared, not paranoid and if you see something, you have to report it,” said McNear.

In his experience, it is not fancy technology that helps crack cases. McNear said it is usually just a nosy neighbor.

“I hope he inadvertently becomes a suicide bomber in his garage trying to build his next device because he certainly is a dangerous person,” said McNear.