Police in Detroit last night announced the discovery of an arms cache of 200 semi-automatic rifles with 25,000 rounds of ammunition, 200 pounds of heroin, 5 million in forged US banknotes, and 25 trafficked Latin prostitutes -- all in a house behind the Public Library on Woodward Ave. Local residents were stunned, and a community spokesman said, "We're all shocked; we never knew we had a library."