The Shunned(2005)

Friday the 13th meets Unforgiven.

After a family is murdered near a remote western town, a US Federal Marshall is sent to investigate. He discovers that the town and surrounding farms is emptying, due in part to the threat of a psychopath having been let loose on the residents. The Marshall has to discover not only who is the killer and how to stop him; but also who let him loose and why.