I have seen the "No TrueFlags Here" You Tube presentation regarding the dropping of a rifle out of the 6th Floor window and the rifle being retrieved from the Huge Gates Roof Top. That's a 4 story free fall that the rifle is taking. I do Not believe that is much of a "plan". If I am thinking about retrieving a dropped rifle from the Huge Gates Rooftop, how about just putting a shooter on Top of that Roof Top to begin with? He fires from that 2nd Floor Height, walks along the roof, goes through the window near the staircase, down the staircase, and then walks out the Huge Gates onto the Elm St Ext. Very Quick, Very Clean Escape. Those Huge Gates were Open on the Towner Film as the JFK Limo was making the turn from Houston St onto Elm St. Those Huge Gates were still Open on the Couch Film. This was a well thought out "plan". The dropping of a rifle 4 stories down onto a roof top is minor league compared to having those Huge Gates wide open for a quick exit.