Justices on Friday concluded a 2nd District Court judge erred by not granting the family's request for a new trial.
In November 2009, a jury ruled against the family of Jessica Nelson and cleared the city of Ogden of any liability in her death.
The 21-year-old Nelson and her 62-year-old passenger Philemon "Bob" Ellis were killed after being broadsided by Eddy Bustos, who was being pursued by police.
Justices said the city's attorney, Heather White, violated a court order and prejudiced jurors when she repeatedly asked questions at trial that amounted to character attacks on the victims.
(Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)