Who fatally stabbed Vanessa Pham, and why?
Exactly a year has passed since the 19-year-old woman's murder, and still those questions have not been answered.
The reward for information has been increased by $20,000, and police have released new photos of Pham's car -- a 2008 white Toyota Scion. Investigators hope the pictures will jar someone's memory and produce some leads.
Pham was last seen at the Fairfax Plaza shopping center in Falls Church. A surveillance camera captured her car as it left the parking lot.
About 30 minutes later, Pham's car crashed along Route 50. Pham was found dead inside the vehicle.
Tonight, family and friends will gather at the Vienna Town Green at a memorial bench dedicated in Pham's memory.
Police ask anyone with information on the murder to come forward and help them close the case.