The teen meets other people in LA so they're suspects too

Alright I have an Idea for a story and I want an outside opinion on it because I'm not very sure about it.

I don't know what I'm calling it but this is the summery

A cynical teenager is sent to live with his deadbeat dad in LA for the summer because his mother was sent to rehab. His dad had re-married so he has to live with his two step-sisters and his younger half-brother. During this time there is an ongoing investigation about a series of murders occurring in the local area. The teenager, having an interest in this sort of thing does a little investigating on his own. He realizes the killer is someone he knows and he has to find out who because the killer is escalating.