The movie is overall well-made and got a story that feels fresh, and one that's seldom told: people taking video footage of gruesome events. The scene that culminates in a police car chase is intense and feels realistic... great direction and camerawork.
Jake Gyllenhaal, the lead of the quality cast, is a highly skilled actor (see Prisoners and Zodiac), but I haven't seen him this good. His character is very unusual and scary, and pretty much a supreme asshole you wish didn't exist. His life is shit (he's lonely, out of money, and seems to have some mental problem), so I almost don't blame him for his criminal behavior.
Rene Russo also gives a great performance, and so does the lady portraying the detective, Michael Hyatt. The latter is very imposing, and pretty much towers above everyone in her (few and short-lived) scenes. Great toughness portrayal there.