What it means to be criminal
There's a scene in The Stranger where Meursault is being interrogated after killing a man. The prosecutor holds up a crucifix and thrusts it at Meursault, who is unaffected (presumably because he is not a Dracula).
The prosecutor is confused, he says something to the effect of "I've done this for a long time, and every single person breaks down crying in front of the cross".
"Of course", says Meursault. "They're all criminals".
He then realizes that he himself, having shot a man six times, is also a criminal.
But the takeaway here is that he didn't. He didn't think of a criminal as a person who has done a crime, but a person who DOES crime. It's an unalienable trait, and one he didn't see himself possessing. It's the othering of "criminals" that enables Meursault to look down on them, and see himself as something else, something superior.
Takeaway
Whew nelly the end of this story hit me with existential dread. Not a fan of that!