1997 Oldsmobile Achieva

Electrical problem
1997 Oldsmobile Achieva 4 cyl Two Wheel Drive Automatic 133857 miles

Okay so I went to go start my car after leaving my mothers the other night and the key wouldn't turn the whole way, it stopped as though something was blocking it. My headlights turn on automaticly when you turn the car on and I would twist the key and the lights would go out, but when I released they would come back on, but still the car didnt start. It didnt even attempt to turn on. Its at a mechanic right now and he couldnt even over ride the safety system. What could it be?
January 29, 2010.

If it lost a lot of power, make sure the catalytic converter isn't plugged. Aso, have you checled fusel pump pressure?