From The TV IV
- mystery writer
- has killed off his most famous character as the series begins and is looking for new inspiration
- married twice, divorced twice
- one ex-wife is his publicist? (1x01)
- raised his daughter himself, thoroughly adores her.
- given name is Richard Alexander Rogers, changed it to Richard Edgar Castle (3x02)
- fences (1x07)
- appears to speak some Mandarin, claims to have learned it from TV (3x09)
- he's a crack shot with a pistol.
- In 1x07 he was able to win the right to take some evidence home for inspection by putting two shots in the center of the target.
- In 3x01 he makes a close shot past Beckett to get a suspect who is behind Beckett with a gun.
- plays the NY Times crossword puzzle (Close Encounters of the Murderous Kind)
- buys a bar, The Old Haunt (Last Call)
- Castle often has psychological insight into the criminal mind. He seems to have derived this from his years of research and efforts at building believable characters. He expresses his insights in terms of stories. When he recognizes that the serial killer Dunn won't be where the FBI expect, he says "It's now how I would write it." 2x18 - Boom
- one of Castle's pet peeves is inappropriate use of English language. In one episode it really bothers him that the killer wrote the note with "your" instead of "you're". Inappropriate uses of irony really get him.
- plays poker with a couple different groups of people. There is a group of writers (Cannell, Patterson). He also plays with a group he calls his Gotham City Group, Beckett's Captain, NY Mayor and Judge.
- due to his fame, he has high profile connections. In the 1x01 he calls the NY Mayor to get Beckett's fingerprints jumped to the front of the queue.
- seems as though his mother doesn't know who his father is, or if she does she never told Castle. (2x15)
- he started writing young, before he was out of college. Kyra Blaine comments when she first met Castle, he was fresh off his first best seller.
- Kyra Blaine (2x12) was an ex-girlfriend. They met in college, dated for three years.
- married twice. First time to Alexis' mother Meredith. Second time to Gina.
- before his association with Beckett, Castle had several encounters with the law (including stealing a police horse while naked), though no charges were pressed due to his high profile associations.