Is it really any mystery what this is about?
This could be a logic puzzle, along the lines of a man found in a room hung by the neck over a puddle of water. “An armed man crashes into a barricade outside the US Capitol and then kills himself when police arrive. Why?”
I’ll go to my grave convinced Dick York was twice the Darrin Stevens than Dick Sargent was.
He could have just been some random crazy person vieing for attention or something much more sinister. We won’t know why he did it until they do their investigation, assuming they ever find out.
Darren is going about his normal day and then Endora puts a spell on him and comedy ensues and no one can figure out why, then Samantha realizes that it is her mother, again.
Repeat for every episode.
Just another very fine person.
York or Sargent?
It’s possible that he shot himself due to feeling overwhelming remorse about destroying his car.
I’m sure the Alex Jones/QAnon crowd have already determined it’s a false flag of some sort.
Some people say this!
Sometimes it was Aunt Clara in one of her muddles. And then Tabitha, but she didn’t usually change her dad.
Geez, I love this place! 
Agreed.
York was a versatile enough actor to play an idiot on Bewitched, Wagon Train and the Twilight Zone.
Not to dismiss the hijack, but wanted to share this article -
Short version, his mother reports that he struggled with CTE from high school football (no verification), and has had a police record (including violence) since his teens, including multiple accounts of assault (including his pregnant girlfriend and a coworker on separate occasions).
His reasons for going to the capitol may have been triggered by recent RW Media, or suicide by cop, but this guy was on the road to a violent end long before Trump I would say.