Przebinda is a gas bag who thinks the Constitutional right to own a weapon of violence is more important than protecting human lives.Texas gets points for being one of only 2 states that have laws which prohibit people with dementia from owning guns.
The second link is really long and has a lot of personal stories of people with dementia firing their weapons.
They may not know their wife from an intruder and after they kill her, may continue asking where she is for the rest of their life.
BBM
Dementia, Alzheimer's Disease and Gun Ownership
.. based on a study conducted in the late 1990s and more recent data about gun ownership among people 65 and older, they estimated that 40 to 60 percent of dementia patients have guns in their households.
Federal laws don't explicitly prohibit purchases or ownership of firearms by people with dementia, and only two states — Hawaii and Texas — prohibit it
Dementia presents a unique challenge to gun safety
Critics of gun restrictions like Przebinda argue that the essential difference between driving and guns is that one is a privilege and the other is a protected constitutional right.
"The two are not the same," he said. "You do not have a right to conveyance. You have a right to self-defense, you have a right to protecting your home and your family that's intrinsic to you as a human being."
He balks at any formal assessment of firearm use among people with dementia, saying it could lead to "a totalitarian system that decides when you can have rights and when you cannot."
Edited to add: Mr. Lester seemed cognizant of what he had done in his interview with police, his description was clear (and terrifying). He said he opened the primary door which was locked, saw a “6 foot tall black male”, was afraid and fired twice, shattering the secondary glass storm door which was also locked.
Being 84 doesn’t necessarily mean you have dementia. My mother, from memory, could still tell you the birthday, address, and phone number of all extended family members and everyone else she knew at 84.
Red Flag laws would have prevented the Missouri shooting of the young man. While Mr. Lester may have been cognizant, we also don't know whether he was in the military and engaged in combat or was in law enforcement. People who suffer from dementia can have very aggressive outbursts as noted in your link. JMO