A 17-year-old Texas high school student was shot and killed while trying to sell marijuana to two suspects on Christmas Eve, police said. The incident took place shortly after 9pm on Sunday when officers with the Irving Police Department responded to a shooting report in the 200 block of Red River Trail. Arriving at the scene, the cops found 17-year-old Brett Adkins, of Plano, suffering from a single gunshot wound to the left chest.