The Brief 18-year-old Julian Luna was arrested on July 29 and charged with murder after a July 26 auto-pedestrian incident on Singleton Boulevard in Dallas. Luna was originally charged with aggravated assault, but the charges are being upgraded to murder. A Dallas teen's charges are being upgraded to murder after an auto-pedestrian incident left another teenager dead. What we don't know:Dallas Police did not detail the altercation that led to the fatal auto-pedestrian incident, or the identities of the other individuals involved in the altercation. What you can do:Dallas Police are asking anyone with information in connection to the incident to contact Dallas Police Det.