The Twentynine Palms Marine accused of killing a prominent dentist and his wife in a DUI crash in May 2015 pleaded guilty in court last month. Mariah Natividad, 22, a lance corporal with the Exercise Support Division on the Combat Center in Twentynine Palms, was driving under the influence and rear-ended a pick-up truck on Highway 62 just east of Juniper Road in Joshua Tree nearly two years ago. The impact sent the truck into the desert where it rolled over several times. Inside the truck were Dr. Lonnie Tiner, 80, and his wife, Patricia, 75. The Tiners died 10 minutes apart the next day at Desert Hospital in Palm Springs. Natividad pleaded guilty April 6 to two counts of gross vehicular manslaughter while intoxicated. She is scheduled to be sentenced June 21.