and twenty years. Thomas was in fact sentenced to 60 months on one of the firearms counts and to 240 months each on the other two, to be served consecutively to one another and to the sentence on the remaining counts. 4 . Thomas suggests in reply that there was no practical advantage to be gained by conceding guilt as to the UPS robbeiy because the government pursued an aiding and abetting theory at trial. However, mere participation in the UPS robbery would not be sufficient to sustain a conviction on the count charging assault on a federal officer, or on the § 924(c) counts, which require proof that the defendant, in addition to being a participant, used or aided and abetted the use or carrying of a firearm. See, e.g., United States v. Bancalari, 110 F.3d 1425, 1429-30 (9th Cir.1997) (<HOLDING>). Thomas was charged with aiding and abetting
holding that mere negative acquiescence  in the criminal conduct of others even with guilty knowledge is not sufficient to establish aiding and abetting holding that no active facilitation of the principals use of the firearm is necessary for an aiding and abetting conviction under  924c holding it was not a surprise or unfair to the defendant for the state to pursue a theory of aiding and abetting at trial when the charging document did not refer to aiding and abetting holding that to be guilty of aiding and abetting under  924c the defendant must have directly facilitated or encouraged use of the firearm mere presence at the scene of the crime and knowledge that the crime is being committed is not enough holding that government proves aiding and abetting of  924c crime when it proves that defendant 1 actively assisted underlying offense or use carry or possession of firearm 2 with advance knowledge of that firearmrelated conduct