[Lucius Cornelius Sulla]

As it happens there are no federal laws against murdering children or adults in any of the 50 states.

[CharlesWayneCT]

Yes, there is. In fact, there are laws about not physically harming adults, and even about not verbally harassing adults as well.

Ramos and Compean were charged for shooting an illegal drug smuggler. Those were all federal charges, including assault with a deadly weapon.

Here is an article that mentions a man being brought up on a Federal Murder Charge

Maybe you were being coy. Obviously, none of the 50 states has a "federal law" on their books. The law is a federal law.

Granted, these laws seem to be based on the 14th amendment.