Authorities say a key piece of evidence in the case of four University of Idaho students stabbed to death in November turned out to be surveillance footage showing a white sedan driving past the victims' home. According to a police affidavit unsealed Thursday, the car drove past three times before the stabbings early on Nov. 13 and was recorded speeding away afterwards. Investigators said they later tracked the car — and eventually, DNA evidence — to Bryan Kohberger, a 28-year-old graduate student in criminology at Washington State University, just across the state border. Kohberger made an initial appearance in an Idaho courtroom Thursday after being extradited from Pennsylvania, where he was arrested last week.