Re: SRT wont start/fire just out of the blue
In automatic Crossfires once the key is turned to the START position, the starter will continue to spin (you don't have to hold the key) until a start occurs or period of time (5-10 seconds or so) has passed. Then it will (should) stop cranking. This is normal.
See if it doesn't stop cranking after awhile. If it does...
It appears that you have a No Start condition. See Post #3 above.
Check for fuel pressure on the fuel rail or spray some starter fluid into the intake. If she'll run while you are spraying, looks like a fuel delivery problem. Let us know what happens.