Hunt is on for ‘serial bomber’ after fourth blast in Austin

AUSTIN — An explosion that seriously wounded two men and rocked a quiet southwest neighborhood appears connected to a string of mysterious and sometimes deadly blasts this month that have fueled fear across the Texas capital, authorities said Monday.

“Clearly, we are dealing with a serial bomber,” Police Chief Brian Manley said.

Manley said a bomb placed alongside a fence had tripwire the men triggered with their bikes Sunday night. The use of a tripwire, he said, reflects a “higher level of sophistication” than the earlier bombings.

Manley said the men suffered “significant” injuries. He said a sweep indicated the area was safe, but he urged residents within a half-mile to remain indoors until 2 p.m. local time.

The chief also said 500 law enforcement officials at the local, state and federal levels have found “persons of interest,” but no clear suspects have emerged. Authorities asked residents to share home-security video for clues.

Austin resident Leith El-Hassan, 42, said he initially mistook the explosion for thunder.

“We don’t know what’s next,” he said. “They have no suspect. It’s just sad that someone is so angry they do this random stuff.”

Nearby resident Richard Herrington, 75, said he heard the blast and immediately knew it was a bomb.

“My initial emotional reaction was, ‘Oh my goodness, I walked my granddaughters right by there,’ ” he said.

The three earlier blasts involved packages left on doorsteps. Manley said the latest bomb “changes things.”

Hours before the blast, Manley had pleaded publicly for the bomber to turn himself in. After the blast, scores of law enforcement officers, including FBI agents, flooded the neighborhood of single-family brick homes.

Texas Gov. Greg Abbott announced the state is committing $265,000 to the effort to solve the bombings.

Frederick Milanowski, ATF special agent in charge, said the tripwire was similar to fishing wire and would have been difficult to see. Investigators were studying the components of the bomb and injuries to the victims to learn more about the explosives, he said.

The bombs may be different, but the bombmaker is the same, he said: “We have a high degree of confidence the same individual built all these devices.”

Two people were killed and two wounded in the earlier attacks.

Sunday’s explosion occurred on the final day of the popular South By Southwest festival, which attracts global leaders in business, technology, music and film.

A tripwire set off Sunday’s blast, police say. Two men were wounded. ERIC GAY/AP