If you know someone is committing murder and you do nothing to stop it, does that make you guilty of a crime as well?
It makes you culpable morally if you could stop it arguably.
It makes you culpable legally if something you did faciliated the murder.
Like Kerry and Harkin swapping spit with the murdering Ortega brothers in Nicaragua or Carter buttboying with Fidel who has killed at least 100s of thousands in Cuber.