8th Cir. Model Jury Instr. (Criminal) 5.01

A person may [also]2 be found guilty of (insert principal offense) even if [he] [she] personally did not do every act constituting the offense charged,3 if [he] [she] aided and abetted the commission of (describe principal offense).

In order to have aided and abetted the commission of a crime a person must [, before or at the time the crime was committed,]:4

(1) have known (describe principal offense) was being committed or going to be committed;

(2) have had enough advance knowledge of the extent and character of [specify the crime] that [he][she] was able to make the relevant choice to walk away from [specify the crime] before all elements of (insert principal offense) were complete;5 [and]

(3) have knowingly acted in some way for the purpose of [causing] [encouraging] [aiding] the commission of (describe principal offense)[.] [; and]

[(4) have [intended] [known] (insert mental state required by principal offense).]6

For you to find the defendant guilty of (insert principal offense) by reason of aiding and abetting, the [government] [prosecution] must prove beyond a reasonable doubt that all of the elements of (describe principal offense) were committed by some person or persons and that the defendant aided and abetted the commission of that crime.

You may infer the defendant had the requisite advance knowledge of the (insert contested element of the principal offense, e.g., knowing possession of a firearm in furtherance of a crime) if you find the defendant failed to object or withdraw from actively participating in the commission of (insert principal offense) after the defendant observed another participant complete (insert contested element of the principal offense).7

[You should understand that merely being present at the scene of an event, or merely acting in the same way as others or merely associating with others, does not prove that a person has become an aider and abettor. A person who has no knowledge that a crime is being committed or about to be committed, but who happens to act in a way which advances some offense, does not thereby become an aider and abettor.]