sci fi in the town of Oblivion, the marshal is killed

Jack Harper is one of the last few drone repairmen stationed on Earth. Part of a massive operation to extract vital resources after decades of war with a terrifying threat known as the Scavs, Jack’s mission is nearly complete. His existence is brought crashing down when he rescues a beautiful stranger from a downed spacecraft. Her arrival triggers a chain of events that forces him to question everything he knows and puts the fate of humanity in his hands.

On another planet which resembles the Old West, a die-hard pacifist is forced to re-examine his ways after an evil alien bandit and his gang murder his estranged sheriff father, take over his home town, and threaten his friends.