REVERE – A 76-year-old Revere man with a prosthetic leg, known to friends and neighbors as “Pops,” is behind bars on charges of selling narcotics and bootleg cigarettes out of a Chelsea taxi company.Richard Picardi Sr. was held on $10,000 cash bail following his arraignment Monday in Chelsea District Court on six counts each of unlawful distribution of a class B substance and violating the state’s drug laws in a school zone. Picardi was also charged with single counts of receiving stolen property and selling cigarettes without state tax stamps.Suffolk County District Attorney Daniel F. Conley said Picardi was taken into custody after Chelsea police conducted an investigation that included undercover officers who repeatedly bought OxyContin, Percocet, and other narcotic painkillers from him. The plainclothes detectives paid cash and, in some instances, traded cigarettes for the drugs, which are unlawful to possess without a prescription.Jake Wark, a spokesman for the prosecutor’s office, said the investigation began in March. The undercover officers engaged in five separate transactions with Picardi, who kept a desk at the Washington Street headquarters of Square Taxi in Chelsea. It remained unclear whether he held any official position at the establishment; since he told officers during the booking process that he was retired and self-employed, according to Wark.Evidence in the case suggests that in addition to taking cash, Picardi also accepted partial payment in cigarettes, which purportedly were later sold at a discount. Police officers paid Picardi $20 and a carton of cigarettes for two 20mg OxyContin tablets on one date, and on another obtained three 20mg tablets for $40 and eight packs of Marlboros.On two occasions, evidence also suggests Picardi sold Percocet and Roxicet tablets to undercover officers when he was out of OxyContin. In the course of the undercover buys, the officers observed him selling cigarettes for $4 a pack out of his desk drawer, Wark said.When Chelsea police executed warrants for his arrest and a search of the premises on April 11, Picardi was personally holding 74, 5mg Roxicet pills and more than $11,000 in cash – including bills that had been marked by Chelsea police in prior drug buys.From Picardi’s desk, police recovered 16 packs of Marlboro Lights that were not affixed with stamps proving that Massachusetts taxes had been paid on them. The investigators also found beneath his desk a total of 21 packages of razors in various brands and styles, as well as five bottles of Drakkar Noir and Thyme Ginger Mint cologne. Investigators believe these items were stolen, said Wark, noting that no contraband was found in other areas of the cab company.”This was not an independent business or an informal corner store,” Conley said. “This was the illegal sale of addictive narcotics by a man old enough to know better.”Picardi is represented by attorney Carmine Lepore and will return to court on June 4.