A substitute teacher was arrested for allegedly engaging in sex acts with a 16-year-old girl in a BMW in Hesperia early Sunday, officials said. The pair were discovered by a deputy checking on the black BMW, which authorities said appeared to be suspicious, parked near the intersection of Ivy Avenue and Alder Street. The teacher, 40-year-old Rakshannah Ranney, was engaged in some kind of sexual activity with the girl in the car, according to the San Bernardino County Sheriff's Department.