A driver involved in a hit-and-run crash in South Boston was looking at his phone when he struck a pedestrian in a crosswalk, according to the Massachusetts State Police.John Murphy, 64, of Dorchester, faces multiple charges, including operating while texting and leaving the scene of a crash that caused serious bodily injury.Police said a 60-year-old woman was struck the morning of Dec. 2 while crossing Day Boulevard in the area of K Street.Investigators said the car hit the woman, knocked her to the ground and the driver then continued to travel toward L Street.Police said the victim was in the crosswalk at the time.She was rushed to a Boston hospital with serious, non-life-threatening injuries, according to police.Following an investigation that lasted 15 days, state police detectives identified Murphy as the driver involved in the pedestrian crash.Investigators believe Murphy replaced the sideview mirror on the driver's side of his Lincoln Town Car in the days after the crash. The car's original sideview mirror was damaged in the crash, according to police.Troopers also determined that Murphy rented a car after the crash, officials said.Murphy also faces charges of operating to endanger, assault and battery with a dangerous weapon, operating after suspension, tampering with evidence and a crosswalk violation.He was booked by state police and transported to South Boston District Court for arraignment Tuesday afternoon.