accomplice
person who actively participates in the commission of a crime, even if they take no part in the actual criminal offense, with the other perpetrators
fixer
person who carries out assignments or solves problems for others
necessary collaborator
person criminally responsible for a crime who cooperates in its execution with an act without which the crime would not have been committed
accessory
person who assists in the commission of a crime, but who does not actually participate in the commission of the crime as a joint principal