§ 433 Accessory tried independently of principal.

Here's a plain English summary of this rule:

Someone who helps a felon commit a crime can be charged and put on trial even if the main person who committed the crime is never charged. The case against the accessory does not depend on what happens to the principal offender.

This means prosecutors do not have to wait for the main suspect to be tried first. They can go after the accessory on their own timeline. It also means that even if the main suspect is found not guilty, the accessory can still be tried and convicted. The two cases are treated separately, and what happens in one does not control what happens in the other.