A former Spokane firefighter, fired for having sex with a 16-year-old girl in a city firehouse in 2006, was found guilty Tuesday of fourth-degree assault with sexual motivation in a case involving another 16-year-old in 2007. Daniel W. Ross, 38, was sentenced to a year in jail with 335 days suspended, ensuring that he will spend at least a month behind bars starting in August, officials said Wednesday.