In my town, there are "sudden killings" of let's say a particular person. No reason why they would be killed or they were a particular target, but everyone is saying " there is no reason to kill this person".

The authorities, in the coming weeks, months do a "shootout" where another person is killed and they declare "in an operation today, we killed the perpetrator of the previous killing. Case closed".

No one is arrested, no suspect is made public before the second shooting and no one asks why no due process was followed.

Its like clockwork and we can count out such instances in more than 2 dozen in the past 20 years if not less.

"How did killing Oswald end the story?"

Exactly. We don't know since "the killer is dead, nothing to see here, keep moving". I give up.

Because he couldn't be questioned.

It removed the ability for there to be a different narrative. Either Oswald was a lone gunman, or you're a crazy person and believe in conspiracy's.

Read up on Allen Dulles.