The California State Library, California History Section at 900 N Street in Sacramento has a great newspaper collection as well. It includes the Mountain Messenger. You really need a date or time period to search the newspaper. It will be a time-consuming search otherwise. These old newspapers often contain lots of good information. Don't neglect the two major Sacramento newspapers as well (the Bee and the Union). They would very likely carry an article on a murder committed in Sierra county.

Chuck Knuthson
Sierra county GenWeb