it's been a long time since I've read it so the details are blurry ...
If I recall correctly a man is sent back in the past and try to go to Oregon (or the Willamette valley)
doing so he gains a reputation as a killer (although he only killed in self defense)
one of the only thing I recall for sure is at one time he must question a suspect (with the sheriff or marshal looking the other way) and use some needles and psychological pressure to get his answers
any ideas?