If Castle and the Rookie existed in the same universe, these are my head cannons on the character's opinions of Castle and his books.
Nolan would be aware of Castle simply because while the celebrity look alike jokes. He's never read any of his stuff before he joined the police academy, but afterwards he gave the first Derek Storm novel a glance.
After she gets together with Nolan, Bailey also becomes aware of Castle because of the celebrity look alike but nothing beyond that.
Tim absolutely hates the Derek Storm and Nikki Heat books. He thinks they're a disgrace to policing and giving people the wrong idea. He's never read any of them.
Lucy was really into all the Castle and Beckett drama. Whole internet sleuth style. She has read a few of his books but plays up how much she likes the them and how many she's read to annoy Tim.
Nyla is actually a really big fan of the Derek storm books. She really appreciates how much effort Castle puts into the details.
Lopez, on the other hand is a big fan of the Nikki Heat books. She really likes her character and it's kind of her guilty pleasure.
Her and nyla have debates about which series is better.
Wesley knows nothing about the books other than the fact that his wife likes them.
Selena saw the Nikki Heat movie when it came out and it left a bad taste in her mouth. She hasn't read or looked at any of his other work because she thinks it'll be just as bad as the movie.
Aaron also saw the Nikki Heat movie when it came out. He also didn't like it but was curious and discovered the Derek Storm graphic novels. He really liked those. Now that he's older, he wants to read the original novels but hasn't found the time.
Gray is not really aware of richard castle, But he does know the absolute legend of Commissioner Kate Beckett. And through that, is tangentially aware of her husband.
Seth actually read some of castles earlier work. But claims to have read all of his stuff.
Penn has not read any of the books
