This movie is a big ol' mess. And the trailers are flat-out lying to you as to what this film truly is. It is not a brother-on-brother crime violence story; so don't let them fool you. What this movie is, what it should be called, is Hey, Watch These Incompetent Law Enforcement Officers NOT Own the Night. But I guess that wouldn't work as well on the poster. There are a few good parts, but they are mostly comprised of when people are shooting at each other... and it's hard to mess that up.
The film, crazily, is titled We Own the Night based on the NYPD's tough sounding slogan. But in the '80s they didn't own the night. Not even a little bit. Drugs owned the night, and that's where the first disconnect with this film presents itself. Joaquin Phoenix is a brother to Mark Wahlberg, both are sons to Robert Duvall. Duvall and Wahlberg are both NYC police officers tasked with bringing down the drug dealers in the city. Phoenix, somewhat ashamed of his straight-laced family, is the manager of a big time nightclub. There's your conflict: Phoenix is the party guy while brother and poppa are by the book. All of which is fine; this concept would work as a movie if not for...
It's essentially impossible to cheer for the cops. They are quite bad at their jobs (according to the script at least), and they don't inspire fear or respect. What they inspire is pity. And you don't want pity as your default world view of what should be a hero tale. The film is also epically long, meandering along without any real point, right up until the ultimately unsatisfying and illogical ending. There is very little that's cool about this film, aside from the opening scene where Joaquin and Eva Mendes do their level best to add a little grit into an otherwise shallow story.
On that note: I quite liked Eva Mendes here, and there are some shots of her that held promise. I think one of them is in the trailer: she's smoking while walking down a hall, and the film slows down to take her in. It's one of the few moments of patience We Own the Night pulls off, trying to show the audience exactly who Mendes is. The rest of it is just a bunch of guys running around with guns and occasionally hitting their heads together. So if you want my advice just check out the trailer a few more times. It's pretty much the best part.