If the engine wont turn over i would start by checking the battery and starter. It could also be anti-theft related, or the motor may have locked up (not common, but does happen).
The vehicles computer uses a signal from the cam position sensor to determine when to fire the spark plug. If the engine does not spin, the computer will not send a signal for spark and/or fuel.
〉 Answered on Jun 13th, 2014 by Helaine Kurot, Owner/Technician at 360 Automotive