What happened?

Recently, we had to replace the starter in my mom's '99 Grand Prix 3.6. After being sold a faulty one and getting a new one, it now turns over but simply won't start. There weren't any indications of problems in the past except for a CEL that was never checked. Plugs were done about five months ago. Could it be the timing belt possibly? Or could the distributor coil or something have died? Afaik there were no issues with it running poorly.

Thanks. And yes, we did double check the starter wires.

Are you sure you didnt fry a fuzeabe link down by the starter? If it doesnt start you have to check for spark and fuel pressure and post back your findings.

1st, they never put a 3.6 in a 99 GP, did you mean 3.8, and if so, is it a GTP, GT or SE?
2nd, do you now have a security light on in the dash?
3rd, did you accidentally arch any wires or see any sparks when you hooked the battery back up.
4th, do you hear the fuel pump prime when you turn the key on before attempting to start?

Yea, 3.8. I can never remember the exact engine size -.-. There were noticeable sparks when connecting the battery terminal to the battery, but I would have expected that. There's no security lights that I know of on the dash. The battery is disconnected right now, so I'll check the fuel pump tomorrow when we put it back on (I was told to take it off to see if it was a security issue). Thanks for the help.