95 Maxima battery and alarm help

[EfrumT]

Okay, I pretty much know nothing about cars, but am in a real bind at the moment. Was hoping if someone here had the knowledge to help me out.

So here is the situation. My friend owns a 95 Nissan Maxima, which the other day I borrowed to drive to school in and accidentally left the headlights on for 3 hours, consequently draining the battery. I jump-started it and then driven home, but then upon the next attempt to start the car (which was the following morning) the battery was dead.

My question is whether it is common for a single draining like that to kill a battery (it is quite old he says). Or, if it could be this other problem which I will explain:

While driving home right after the car was jump-started, the "alarm" was going off. I say it in parenthesis because he had disabled or done something to the alarm previously, so the interior lights were simply flashing along with some clicking like if I had the hazard lights on. (I'm not sure whether it is the manufacture alarm or after-market, I can find out though)

Could the alarm possibly have been running all night after the jump-start and therefore drained the battery again? Or is it simply dead and i'm gonna be out $180 for a new one. Kinda need to know pretty quickly lol.

Thanks