US officials link bombing to 3 others in Austin, Texas

By Michael Hernandez

WASHINGTON

Police have found similarities in a bomb exploded Sunday night with three other devices that have detonated in Austin, Texas, officials confirmed Monday as they warned of a "serial bomber" on the loose.

The fourth explosive detonated shortly after police appealed to the person responsible for the three previous bombings to turn themselves in. Two people who were walking on the side of the road were injured.

The 22 and 23-year-old male victims are in stable condition at a local hospital.

Austin Police Chief Brian Manley told reporters authorities are working to determine whether or not a specific ideology is behind the attacks, saying it is too early to determine if they are terrorism-related or are possible hate crimes.

"As we look at this individual and the pattern and what we're looking at here, we will have to determine if we see a specific ideology behind this or something that will lead us along with our federal partners to make this decision," he said.

The device that exploded Sunday night was activated by a trip wire, with authorities describing it as being more sophisticated than previous iterations, which were packages left on the victims’ doorsteps.

"With this tripwire, this changes things," said Christopher Combs, who is leading FBI efforts in the case. "It's more sophisticated. It's not targeted to individuals. We're very concerned that with tripwires a child could be walking down a sidewalk and hit something."

Authorities are warning area residents to remain in-doors, and Manley, the police chief again asked the suspect to reach out to the authorities "so that we can put this to an end.

"There are innocent people getting hurt in this community and it needs to come to a stop," he said.

The explosions began March 2 when Anthony Stephan House, 39, was killed after opening a package left on his doorstep. Ten days later Draylen Mason, 17, was also killed and his mother was injured under similar circumstances.

Esperanza Herrera, 75, was critically injured the same day Mason was killed.

The Professional Golfers Association is set to begin its Dell Technologies Match Play in Austin on Wednesday.