This is interesting. I like case fics also I like how your story format reads like an episode and the personality that you have already given to Bertha. I know that it's been a while since you have updated but I hope that you will continue.

Always glad to see more stories that focus on *cases*, rather than 'shipper fics (which I don't care for). Hard to tell where this story is going to go, but hopefully it'll be a good one.

My criticisms are mostly technical:

-I think this could've used another look over in terms of punctuation (missing a lot of commas), capitalization, and spelling (not sure if you mean "site", which is an awkward choice of word, or "sight".) ("bad enough than her geek of a friend", "...ends up dead way later")
-Watch to make sure you don't slip into present tense.
-Something like saying a character is racist in their description is kind of awkward as well. Much better to show something like that in what they say and do.
-With characters you invented, you can pretty much decide what they would do or how they would talk. With the detectives, however, I recommend rewatching a couple of episodes if possible to get a feel of how they talk. (You should be able to find one or two episodes online, or at least some clips on them). I don't really see Lilly saying "Perhaps", for example.