This is from the movie jacket:

 

A corruption scandal fractures a family of New York City cops in this generational drama about homicide detective Ray Tierney (Edward Norton), who's tasked with investigating a precinct run by his brother (Noah Emmerich). As if that weren't enough, Ray's fellow officer and best friend (Colin Farrell) may turn out to be dirty. Directed by Gavin O'Connor, the film features a high-octane supporting cast that includes Jon Voight and Jennifer Ehle.

 

This is a dark, dark movie.  I just couldn't watch some of the scenes.  In fact, a couple were what I like to call ultraviolent.  Still, the cast and story line were fantastic enough for me to recommend it.  Realistic?  You decide.