For all intents and purposes, Gwen Stacy was probably already dead as she plummeted to the waters.  Remember, Gwen was not a superhero and not used to falling off buildings like the Black Widow, Black Cat, Sue Richards, etc.  She would have died of fright (a massive heart attack) on the way down.  All this would be the case if she had been awake/conscious.  If she was unconscious, she probably would have died when she hit the water (even breaking her neck upon impact).  Being unconscious she would not have hit the waters at a clean (proper diving) angle.  Yes Peter's catch saved Gwen from hitting the water, but it did not save her life.  Instead it broke her neck.  I don't think Peter  "killed/murdered" Gwen.  I think he tried to save her.  Unfortunately, he just wasn't fast enough or in the right place at the right time to do so.  In conclusion: ultimately, Gwen's death was caused by Norman Osborn, the Green Goblin.

This is an easy answer today - The Green Goblin.  But for a long time when I was a kid, I found the Goblin's purple prose blame-game on Spider-Man disturbingly credible.  The death of Gwen Stacy is a sort of perverse re-capitulation of the origin of Spider-Man.  Uncle Ben dies.  It's not directly Peter Parker's fault, but the guilt is very real (and very Catholic, as Frank Miller has noted).   So Uncle Ben dies because of the way Peter Parker is, and Peter Parker accepts the responsibility being Spider-Man saddles him with.  And THEN Gwen Stacy dies - because of the man Peter Parker became!  Talk about damned if you don't, damned if you do!

Of course, by the time I was in high school the story didn't have the same impact - by then I realized skydivers routinely jumped from much higher than Gwen fell.  But that fateful "Snap" sound effect is still bouncing around in my psyche somewhere.  Wow.  And it must say something that I was willing to believe the villain's version of events - that heroes sometimes act futilely, when they are needed most.

Heavy stuff.  Well, time to get off the couch.  It's pop psychobabble like this that somehow put me over the 9000 post mark.  Thanks for pointing it out, William!

Saturday 12/14 toss-up: Spider-Man's arch-villain - The Green Goblin or Doctor Octopus?  (as always, feel free to wing it)