Austin Police are offering more money in hopes of finding the person behind a string of package bombs.
The bombings have killed two people and injured two others this month. Austin Police, the FBI and ATF are following up on hundreds of leads.
Police announced on Sunday, they are doubling their $50,000 reward offer for information leading to the bomber’s arrest. Governor Greg Abbott offered $15,000 as well, bringing the total reward to $115,000.
The ATF in Houston tweeted Sunday "We are with you, Austin" as the ATF, FBI and local police are "using every resource available" to find the person or persons responsible for the package bomb murders.
"These events in Austin have garnered worldwide attention and we assure you that we are listening," said Interim Austin Police Chief Brian Manley.
Chief Manley called the collaboration among law enforcement “unprecedented” as he announced the reward increase.
"The person or persons understands what that message is and are responsible for constructing or delivering those devices," he said.
Manley told reporters more than 500 agents are involved in the investigation, and they've already followed up on more than 400 leads. Officers in Austin have also responded to more than 700 calls for suspicious packages.
"We hope this person or persons is watching and will reach out to us before anyone else is injured, or anyone else is killed out of this event."
The bombings killed 39-year-old Anthony House and 17-year-old Draylen Mason. Their pictures are on the FBI poster seeking information. The first bombing happened March 2nd, when a package detonated at House's home in northeast Austin. Two more bombings happened March 12th in east Austin, killing Mason and injuring his mother, and injuring another 75-year-old woman at a different home.
Police are pleading with the bomber, or bombers, to come forward.
"We want to understand what brought you to this point and we want to listen to you,” said Chief Manley.
Austin Police say someone made threats against a South by Southwest concert series event Saturday night. Police say the promoter canceled the event because of those threats. Police were able to track down the suspect, 26-year-old Trevor Ingram, and arrest him for making terroristic threats. After interviewing him, police do not believe he is connected to the package bombings.