What is the case law on aiding and abetting murder?

The underlying facts are set forth in our prior opinion in People v. Manzanares (Mar. 19, 2010, G040381) [nonpub. opn.], which we incorporate by reference. They show that in 2005, at the age of 19, petitioner was involved in a gang fight that culminated in the shooting death of a rival gang member. Although petitioner was not the shooter, he was convicted of first degree premeditated murder and other crimes based on aiding and abetting principles. The jury also found true a special circumstance allegation the murder was committed to benefit petitioner's gang. Accordingly, the trial court sentenced petitioner to life in prison without parole for that offense. As explained below, the court also enhanced petitioner's sentence significantly because his crimes were gang related and a principal fatally discharged a firearm.