It doesn't have to be a person and it doesn't have to have murderous intent.
It is the act of removing something by throwing it out a window.
( gronkpan , a friend, Sat 25 Aug 2007, 11:24, archived)

I believe is more used for tossing out a personage:P
But, yeah, it can mean anything.
( riverghost It's Sprooooooooutmaaaaas!, Sat 25 Aug 2007, 11:41, archived)