Monty Wallis joined the Yellowstone County Sheriff’s Office in 1993, working as a Reserve Deputy in both the Patrol and Detective divisions. In 1997, he received the Sheriff Office’s Award of Merit, for the night-time evacuation of the residents of a burning apartment building in downtown Billings. In 2011, Sheriff Mike Linder tasked Wallis with the design, creation and implementation of the department’s Cold Case Unit. He was then asked to coordinate the unit in March 2012 and continues to serve in that capacity today. Since its inception, the unit has solved two of the highest profile cases it was assigned, the 1973 Cliff & Linda Bernhardt homicide and the 1998 Miranda Fenner homicide.