The Reckoning (2014)

Justice will come for you.

When a detective is called in to investigate the roadside execution of his partner, he discovers at the crime scene a data card from a video camera. The card contains footage shot by two runaway teenagers who are making a documentary about the drug related death of a sibling. The detective retraces the teen's journey and soon begins to uncover a trail of the dead that leads all the way back to police headquarters.