The crash that killed a father and his son was captured on video, and police are investigating whether the suspect in the case was aware of the footage.
The video shows a black BMW speeding away on Highway 99 near the intersection of the Arizona and Colorado borders in the early hours of Monday.
Authorities said it was believed to be the vehicle that struck a car earlier in the day on Interstate 15.
It was a brazen attack on a busy highway and it was only captured on the video, authorities said.
The driver of the BMW, a man, is seen fleeing in the car, which was covered in blood.
The victim, his father, a 56-year-old woman and her 4-year old son were in the backseat.
The driver of a white Honda Accord was also in the passenger seat.
The man was wearing a mask.
The suspect fled on foot.
He was later caught on surveillance video, officials said.
Authorities said the vehicle had not been reported stolen and that the family has been notified.