My son was shot and killed on the streets of jersey city, nj. The killer was not found. Can I sue the state or city for worngful or accidental death

You can sue, but it will be thrown out of court, unless there is a lot more to the story.  There's nothing you've said that connects either the city or the state to the shooting, other than it happened on the street and the killer wasn't caught.

Your wrongful death action would be subject to the New Jersey Tort Claims Act.  Before you could sue, you would have to file a notice of claim, within 90 days, and then give the State and/or the city six months to investigate and try to resolve the claim.  The statute also gives the government immunity from claims that are only based on a lack of police protection, among other things.

The Tort Claims Act doesn't apply to suits in federal court for civil rights violations, but I simply don't see anything like that here.

If there are other facts, that you think tie the city or the state more closely to this crime, you should discuss them with a New Jersey attorney near you.  Place that you can find qualied counsel include the bar association's Lawyer Referral Service (which should be listed in your telephone book) and our website, http://attorneypages.com