Chelsea bomber made 'weapons of mass destruction' using sling shot ammo, candy-making ingredients

[Rahami's] shopping list allegedly included electronic circuit boards and "electric igniters" intended to be used "for fireworks," as well as 200 "hardened lead milling balls" and two packages of .50 caliber "sling shot ammo." Those items, Licata wrote, were used as detonators and shrapnel in the pressure cooker bombs that Rahami placed in Chelsea.On Aug. 10, Rahami purchased five pounds of citric acid from eBay. The listing for the item described it as "great for bath bombs and candy making." In addition to its many benign uses, Licata noted that citric acid is a "precursor chemical commonly used in improvised explosives." It can be used to make the explosive compound HMTD, which was reportedly found inside a second pressure cooker bomb in Chelsea that failed to detonate.