A third explosion since March 2, including two reported explosions Monday morning, is sparking concern that a serial bomber may be targeting Austin residents. Austin Police Department is investigating all three incidents for potential links but no confirmation has been made yet. Out of 439 confirmed bombings reported to the Bureau of Alcohol Tobacco and Firearms during the 2016 calendar year, only three involved someone hand-placing a box containing explosive material, according to the ATF's 2016 Annual Explosives Incident Report, the latest report available on the ATF's public website. The report reviews bombing and explosives-related incidents and threats from information reported to the United States Bomb Data Center through the Bomb Arson Tracking System by its nearly 2,500 interagency partners and 12,153 registered users, according to the report. The most commonly used delivery device in 2016 was a pipe bomb, used 61 times that year. 12 of the total involved a victim-operated switch. The most often-used type of explosive used was fireworks, used 126 times, followed by flash powder, used 46 times. In 2016, of the 439 bombings nationwide:
- 178 targeted homes;
- 22 targeted schools (up from 16 in 2015);
- and 2 targeted churches (down from 6 in 2015).
