Manley said the cooperation and support from federal partners has been "unprecedented."
More than 500 agents between the police, the Bureau of Alcohol Tobacco Firearms and FBI are involved in the investigation, he said. Agents have followed up on 435 leads that have resulted in 236 interviews.
Manley also described the process of the investigation, which includes 8 a.m. and 5 p.m. briefings every day. A command center, comprised of local and federal agents, has been set up to handle the deluge of tips.
“The process is complex, but it is working for us as we go through all these tips,” he said.
Manley said officers have received 735 calls for suspicious packages as of Sunday.
On March 2, 39-year-old Anthony Stephan House died after a package at his home in Northeast Austin detonated. Then, on March 12, police responded to two more package bombings in East Austin -- one that killed Draylen Mason, 17, and injured his mother, and a second attack at another home that sent a woman in her 70s to the hospital with serious injuries.
Manley said that woman is “still fighting for her life,” but would not give any further details on her condition.
Original story: Austin police and the FBI will hold a news conference at 2 p.m. Sunday to announce an increase in the reward for information that leads to the arrest of the person or people responsible for the three package bombs that have killed two people and injured a third in East Austin.
The news conference comes a day after a bomb threat at an East Austin music venue forced the cancelation of a South By Southwest show by The Roots.