An Outrage in East Haven, Conn. Hispanic residents and civil-rights advocates have raised alarms for years about the police in East Haven, Conn. Their claims gained chilling corroboration on Tuesday. The Federal Bureau of Investigation arrested a sergeant and three officers on charges of terrorizing the town's Hispanic neighborhoods, stopping and detaining people, searching businesses without cause, beating people in handcuffs, smashing a man's head into a wall. The charges echoed what the Justice Department reported in December, accusing East Haven police of widespread "biased policing, unconstitutional searches and seizures and the use of excessive force." This was made more appalling when the mayor, Joseph Maturo Jr., was asked by a reporter how he would respond to the arrests and said that he might have tacos for dinner. First, he said he was joking. When it dawned on him that snide flippancy was the wrong response to grave accusations of police brutality, he said he was sorry for his "off-collar comment." That is not enough. Mayor Maturo should now resign. He has shown a stunning incapacity for understanding the severity of the scandal in his government and has been fatally compromised by his knee-jerk support for the tainted police department and its chief. The mayor's repugnant remark is the least of it. This case is about institutional brutality and oppression. The East Haven case is one squalid part of the far larger furor over immigration, where Spanish-speaking people are met with suspicion and abuse and states and localities rush to pass laws empowering local police officers to harass presumed illegal immigrants. Racial-profiling is flourishing in this climate, and the Obama administration has rightly stepped up efforts to fight it. Judging from the racism so casually exhibited by Mr. Maturo, it's going to be a long struggle.