F.B.I. director James B. Comey speculated that criticizing the police has caused crime to increase.

He wasn't reporting some study, just musing out loud at the University of Chicago Law School.

Mr. Comey’s remarks caught officials by surprise at the Justice Department, where his views are not shared at the top levels. Holding the police accountable for civil rights violations has been a top priority at the department in recent years, and some senior officials do not believe that scrutiny of police officers has led to an increase in crime. While the department had no immediate comment on Friday, several officials privately fumed at Mr. Comey’s suggestion.