Hunting deer or elk and shooting uphill or downhill is different from shooting flat.
Really? What years were you there? My buddies wife works for the FBI in Los Angeles as a forensic pathologist. Maybe she remembers you
What you described would be more applicable to someone shooting a deer, elk, or some other individual target at a considerable distance, and using a type of rifle that would require making specific adjustments. In this case, the individual was firing indiscriminately into a large crowd from a stable, elevated position. He was simply putting rounds down into the general area in the hope of hitting as many people as he could. It would require nothing more than a basic understanding of how to operate the weapon.
Similarly, the article posted by Walter makes numerous errors. Firstly, it doesn't require much physical effort at all to fire the type of weapons that he used. No 'incredible strength' is required to keep them 'on target' when the target is a concert full of people, and clearing a stoppage is as simple as it is on any other similar rifle. Also, it may well be the case that these weapons would be prone to overheating and jamming when being fired for a considerable length of time, but the shooter obviously considered this by ensuring that he was equipped with numerous backup rifles. Heavy, belt-fed types of machine guns often require the operator to switch barrels when firing them for a sustained period to avoid a 'runaway gun' or melted barrel; but this wasn't a concern here. As for the enclosed space, build-up of smoke, and issue of the fire alarm - he was firing from an open window; it was a ventilated room and he may well have done something as simple as sticking a condom over the smoke alarm, if not disabling it beforehand. People read far too much into these events.
