These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Kit Nelson is a Serial Killerdespised by all the other hardened inmates in Alcatraz. He murdered his brother when he was an 11-year old boy by strangling him to death. He would later use his brother's death as a motif for all his subsequent murders. His pattern consisted of breaking into a young boy's bedroom at night and abducting the kid at knifepoint by threatening to kill his siblings or parents if he didn't comply, leaving a flower behind in his place. Then he would force them to take part in his late brother's favorite hobbies for a few days, and strangle them to death in a bomb shelter with murderous glee. He drops off the boys' bodies back where he abducted them, their bedrooms.
Paxton Petty is a Mad Bomber who plants mines in public places to enjoy watching people get blown apart. During the Korean War he planted mines in the local children's playgrounds to eliminate potential Child Soldiers, for which he was sent to a military prison. After getting out he starts to plant more mines around San Francisco to kill as many random civilians as possible, including in elementary school yards. He traps Hauser on one of the mines, but modified the bomb such that the bomb disposal professional would inevitably be killed during the dismantling procedure no matter what they did.