SAN DIEGO — The June head-on crash that killed two off-duty police detectives and a Ramona woman who was driving the wrong way on the freeway was an accident, according to a recently released autopsy finding by the county Medical Examiner’s Office. Sandra Lee Daniels, 58, had a small amount of Valium in her system but no alcohol and normal glucose levels when she got onto southbound Interstate 5 in San Ysidro and headed north, the autopsy report said. Daniels slammed head-on into a car driven by Detective Ryan Park, 32, killing him and his wife, fellow Detective Jamie Huntley-Park, 33. Autopsy…