Cells are not so resilient that a bullet will simply separate them and leave them otherwise intact. It may or may not be possible in principle to tell "which cell goes where" if you were to separate them, but a bullet to the head doesn't even give you something that convenient to work with.
You're talking about a "creamed" brain - one in which the individual cells are separated from each other on an individual level. I was explicitly specifying a brain that is not creamed, but rather, we might say, shredded. I did admit that I didn't know the specifics, so I'm not 100% sure that a bullet merely shreds the brain. I'm no ballistics expert.
Remember paper shredding? We used to do this to hide secrets. Many people still do it. But it doesn't work any more. The shreds can be reconstructed. Now with scanners and computers the process can b...
From "Academics Doubt Impact of Osama bin Laden’s Death":
See also Lost Purposes, The Importance of Goodhart's Law, & Faster than Science.