Dozens of people had gathered for a family reunion at a modest home in this small farm town last September, when a gang member walked down the sidewalk and fired a shot into the air. Junior Munoz immediately confronted the shooter because there were children attending the family party. A quarrel ensued, and minutes later, Munoz lay dying in the street from a gunshot to the chest. His death marked the third gang-related fatality in nine months in this rural city and served as yet another reminder of the gang violence invading farm towns tucked amid Northwest orchards and fields. Nearly two dozen slayings last year were believed to be related to gang activity east of the Cascade Range, which divides the bustling metropolitan regions in western Washington and Oregon from largely agriculture-driven cities and towns. In Quincy, the slaying of Munoz also marked a turning point for city officials, who agreed to pay $130,000 for a software program that will trace gunshots to the spo...