In retrospect, the 2013 arrests of 20-year-old Rhode Island heroin dealer Victor “Fat Boy” Burgos and his 19-year-old accomplice were the earliest warning signs that a wave of deadly synthetic opioids had hit the US black market. Between March and May 2013, the duo sold heroin laced with an unknown second drug. The tainted product led to the lethal overdoses of 14 people. “I am going to spend the rest of my life in jail because of all those overdose deaths,” Burgos told the mother of one witness to him selling the adulterated heroin, as the Providence Journal reported . After an investigation, Rhode Island health officials figured out the chemical identity of the mystery drug: a man-made, never-before-seen opioid called acetyl fentanyl. “Probably it was already in lots of places besides Rhode Island,” medical anthropologist Jennifer Carroll of Brown University told BuzzFeed News. “But that’s where we noticed it first.” Now five years later, fentanyl and its chemical cousins kill more people in the US than any other drug — accounting for around 20,000 deaths in 2016 and an estimated 25,000 in 2017. These synthetic drugs, used for decades in cancer and hospice care, are 30 to 50 times…