New York police conducted more than 200,000 frisk searches in the first three months of this year, a 10 percent increase from the same period last year, even as critics say the practice often is racial profiling. New York City Mayor Michael Bloomberg and Police Commissioner Ray Kelly have long defended the program as one that saves lives and has helped bring violent crime down to historic lows, making New York one of the safest big cities in America. But the New York Civil Liberties Union and other groups say that black and Latino New Yorkers are stopped with alarming frequency, even though in the great majority of cases they are found to have done nothing wrong.