(Caldwell, ID)  --  A former sergeant with the Washington County Sheriff's Office is awaiting sentencing, after pleading guilty in Idaho to having sex with a 15-year-old boy.  Prosecutors say 46-year-old Michael Alexander of Lake Oswego met the boy through a dating app.  Officials say Alexander entered the plea earlier this month in Canyon County court to felony charges of lewd conduct with a child.  He was arrested about a year ago and resigned from the sheriff's office afterward.