There seems to be a "cops go to LA" mini-theme on TV this week. Both Castle and CSI did it. And they're also both examples of the kind of story where someone close to the main character is killed/victimized and the main character goes after them despite being too close to the case and ordered to stay off it. I'm tired of that cliche. Once in a while I'd like to see a protagonist have the good sense to recognize that his or her personal involvement could be an impediment to solving the case. More importantly, I'd like to see that protagonist trusting his/her friends and partners to conduct the investigation on their behalf and do right by them.
I don't know about CSI, but Castle wasn't being a cliche. In fact, the show was very obviously doing a homage to Beverly Hills Cop.
1) A cop friend getting killed in LA. Check
2) LA cop busts them for illegal break-in. Check
3) LA cop ultimately turns friendly and helps in the investigation. Check
4) LA cop is given hotel bathrobe as gift. Check