NEW YORK (AP) — A wave of pharmacy robberies is sweeping the United States as desperate addicts and ruthless dealers turn to violence to feed the nation’s growing hunger for narcotic painkillers.From Redmond, Wash., to St. Augustine, Fla., criminals are holding pharmacists at gunpoint and escaping with thousands of powerfully addictive pills that can sell for as much as $80 apiece on the street.In one of the most shocking crimes yet, a robber walked into a neighborhood drugstore last Sunday on New York’s Long Island and gunned down the pharmacist, a teenage store clerk and two customers before leaving with a backpack full of pills containing hydrocodone.“It’s an epidemic," said Michael Fox, a pharmacist on New York’s Staten Island who has been stuck up twice in the last year. “These people are depraved. They’ll kill you.”Armed robberies at pharmacies rose 81 percent between 2006 and 2010, from 380 to 686, the U.S. Drug Enforcement Administration says.