Sharing home cam footage with cops to help with a murder?

An 18 year old kid was shot on my street last friday. I live in a pretty violent part of this hell hole country and despise the cops. I have a camera in front of my house over-looking the street, and the cops have came over twice asking to see the footage and both time I've refused (even though there is nothing on our camera).

I am feeling kind of guilty because if my camera had something on it that could catch the murderer i'd feel bad for withholding it for the families sake, but on the other hand cops here barely ever catch murderers and have basically gone on 'protest leave' after the BLM protests and my city voting in a 'progressive' DA so they pretty much let crimes happen in front of them and don't do shit. All in all I am pretty conflicted on this and can use some advice. btw my camera didn't catch anything, so now I'm just worried of the cops retaliating against me since I said no to them.

Also as I was typing this i just saw a news story on it that says the murderer was spotted ducking out into someones front yard on their camera two blocks away from me (he wouldn't have passed my house) and then getting into a car and heading away from where I live (again wouldn't have passed my house). The first officers who came by an hour after the murder wouldn't have known that when asking for the footage, but the one who came by today definitely would have so wtf.