The fire alarm was set, not the burglar alarm - - but the theory is the killer didn't know what was set or not set, just the light was on so something was working.

I have gone in and out that basement window myself - not so hard.

But you can't put something in the windowwwell and climb over it and out - - and you can't get in the window well and turn around and grab something off the basement floor and pull it in the window well with you. Just doesn't work.