What is the test for a special circumstances murder, based on murder committed in the course of robbery, against an aider and abettor?

Thus, as applied to Cabbel, "[i]n order to support a finding of special circumstances murder, based on murder committed in the course of robbery, against an aider and abettor who is not the actual killer, the prosecution must show that the aider and abettor had intent to kill or acted with reckless indifference to human life while acting as a major participant in the underlying felony. [Citations.]" (People v. Proby (1998) 60 Cal.App.4th 922, 927, fn. omitted (Proby).)