(Chicago Sun Times) — You probably guessed as much, but a White House study released Wednesday now confirms it — Chicago criminals really are on drugs. A startling 83 percent of men tested following their arrest in Cook County last year tested positive for at least one illegal drug, more than any of nine other major U.S. cities, according to the report released by U.S. Drug Czar Gil Kerlikowske. More than half of all inmates tested on admission to the Cook County Jail came up positive for marijuana, while a quarter tested positive for cocaine and more than one in 10 had heroin or other opiates in their urine. One in five tested positive for multiple drugs. “It’s assumed that most people going through here either have drugs in their system or are in withdrawal when they are booked in,” said Tom Dart, whose jail staff have to deal with thousands of addicts each year.