Mayor Anthony A. Williams was in Las Vegas two Mondays ago. But if he’d been back home, he’d have seen a sight worthy of Bugsy Siegel. According to mayoral spokesperson Peggy Armstrong, someone hung a dead pigeon from the roof of One Judiciary Square down to precisely outside the mayor’s window. “[The Metropolitan Police Department] is addressing and looking at it,” says Armstrong. A source close to the mayor adds that extra guards have been added to his security detail. This isn’t the first time Williams has faced an implied threat: As chief financial officer, he was given bodyguards in the wake of threats following his 1996 firing of dozens of staffers.