On most of the mobile homes I'm familiar with, the outside storm door closes automatically, they have that arm thing on the top that swings it shut. But I recall the mom saying the latch didn't work, so they kept the inside door shut. What if they didn't, and he pushed that door open without anyone seeing him? Our storm door gets to within 5 or 6 inches of the door facing and then slams shut. Used to irritate me to pieces when my stepkids and then my grandkids would push it wide open and then turn it loose, because it is really loud when it closes.