Just how much did the police tamper with bodies?

Im new here and im guessing this has been discussed before. If so just delete this thread.
But this really has me wondering of what really happened.
According the the autopsy of dylan, a bullet entered his head from the left temple and went out the right side(the bone on his left side was bent inwards, as well as power blast on his left side). Yet in the death photos AND the police drawing, we are shown that he is gripping the pistol with his right hand and it is under his leg.
I know he was left handed, and still occasionally shot weapons with his right hand, but this autopsy/ photo thing has it all in the air.
The police also noted that the pistol was found with a round still in the chamber, meaning he had to of kept the magazine inserted while he killed himself, allowing for another round to be loaded after the shell ejected (as apposed to chambering a round and removing the mag). His only functioning magazine was noted to be "found in the library with 3 rounds loaded". Where exactly in the library? Hopefully next to their bodies or this REALLY would be up for question.
BUT in the photos, what we all believe to be his pistol that he is gripping and partially under his leg, absolutely does not have a magazine in it.
Did the police unload his tec 9, and place it in the wrong hand and under his leg? If they knew the shooters were dead, why did they feel the need to move their firearms around?

Welcome to the site

Popular question when the photos were released. Best/most common answer is that the bodies were moved to search for explosives.. that I'm fairly sure was confirmed by authorities.

Dylan actually fell forward onto Eric's legs and the gun fell between his legs. The police most likely kicked him over to see if he was still alive and to check for bombs/additional weapons. He wasn't actually gripping the gun. That is just the position he ended up in after he was pushed over. Or it's possible that in his last few seconds, he rolled himself over onto his back while he was dying.

They were afaik moved around a bit by the first police team taht arrived, searched for explosives.
I doubt this required the bodies to be moved around all taht much, but I think its possible taht for example Eric was found laying on his right side and moved to his left side so that PD could check under his body for stuff.