Calling CrimeStoppers is some other bullshit. If it doesn't concern you, you should stay out of it. People will say and do anything for some cash, so fuck that nonsense.
However, if somebody smokes your man in front of your face, that is your business...and you should be able to deal with that however you see fit. Purposely killing an innocent violates the street code itself, so why can't you say what you saw? Like I said before, you gain NOTHING by protecting somebody that just killed a loved one....and you shouldn't be expected to protect that cat...fuck him.
If somebody killed somebody I loved, I'll put that on the streets and leave it as a race between the streets and the cops (because the streets talk). Know your enemy...if you don't, don't carry and don't pull. If you do carry and you do pull on somebody that has nothing to do with what you're about, you're in violation and should no longer be protected by the streets or the codes. I personally would not retaliate for a friends death...because none of my folks would want me to jeopardize my own life and risk losing it as well.
Understand, I'm not a hood cat. I agree with no snitching, but when somebody just does something fucked up and you have nothing to do with anything...fuck them.