NAC - Draining Battery

[Dan DiBiase]

Trying to diagnose a draining battery (it's new) on my son's '99 Impreza 2.5RS 
from 2 hours away.... He has to jump it every time to run it, 

and if it sits off for even a few minutes after running, it requires a jump to 
start again. Could it be the alternator?  I was thinking it must
be something in the electrical system draining the battery when the car is off, 
but for it to happen within 5 minutes of the car being off seems
unlikely.

 Dan D
'04 A4 1.8Tq MT-6
Central NJ USA