We know that's not true because the police stated that the sketch was no longer relevant immediately after EM was arrested.
No need. I heard Brandon himself claim that he promised not to share that he knew who the shooter was because it would hinder the investigation. Meanwhile, the police were very clear after EM was shot that they only learned about it a couple of hours prior to EM being arrested.
Unlike you, I've lived with firearms my entire life. Being able to legally own guns does not dictate how households secure their guns, or how family members feel about one another having access to them. I made my first husband keep his firearms under our waterbed so he'd have to drain the waterbed before having access to the guns. I didn't trust his temper. We've already established that Brandon is a known hothead.
In my current household, we have a safe in the attic. Usually, every family member has access to the key to the safe because we're all very level headed. My husband is the most even tempered person I've ever know. But when any of my children were going through a difficult time emotionally, I have instructed my husband to secure the key.
My children are adults and one of them talks about getting a handgun of his own. I tell him not while he's living under my roof. Law doesn't dictate family rules. While grandmother's underwear drawer doesn't provide much protection from grabbing a gun while in passion, it does slow someone down, especially if grandmother rarely leaves her room. For all we know, the gun was in a small gun case in the drawer too.