A motorcycle officer with the Sacramento County Sheriff's Department has been struck and killed. Authorities say 43-year-old Lawrence Canfield was a 13-year veteran. He had been assigned to the Rancho Cordova Police Department, which contracts with the sheriff's department. Sgt. Tim Curran, a spokesman with the sheriff's department, says the deputy was struck by a 79-year-old driver shortly before 2 p.m. Wednesday. The driver was detained, and the crash remains under investigation.