Was street racing the cause of these two deaths?

Late Sunday night in Detroit, a red Dodge Charger, traveling at a high rate of speed, hit a Pontiac G6, killing both the female driver and male passenger.  It is unknown whether the Pontiac was also speeding.  It appears the cars may have been racing.  According to reports, the driver of the Charger fled the scene, but a 22 year old man who later came to the scene to remove items from the Charger was detained for questioning.  The investigation is ongoing.