Is an individual an accomplice if they were present at the scene of the crime?

Generally, an individual is an accomplice if she acts "'with knowledge of the criminal purpose of the perpetrator and with an intent or purpose either of committing, or of encouraging or facilitating commission of, the offense.' [Citation.]" (People v. Prettyman (1996) 14 Cal.4th 248, 259.) Typically, an accomplice "'gives aid or encouragement'" to the perpetrator in the commission of the offense. (Ibid.) "[N]either presence at the scene of a crime nor knowledge of, but failure to prevent it, is sufficient to establish aiding and abetting its commission." (People v. Campbell (1994) 25 Cal.App.4th 402, 409.)