Authorities are still investigating three bombings that have killed two people in Austin. Local police say the incidents are related but the motive is still unclear.
The first bomb killed Anthony House on March 2, the second killed a 17-year-old boy and the third critically injured a 75-year-old woman.
The packages were hand-delivered in mundane boxes.
Combined with recent school shootings like the Parkland High School shooting in Florida last month, students are worried that the violence in Austin may have been inevitable.
Texas governor Greg Abbott announced a reward of $15,000 for information leading to the arrest of the person responsible.