Under what circumstances will a jury overturn a conviction for first degree murder based solely on a felony-murder theory?

We conclude that under these circumstances the jury likely considered the felony-based murder and special circumstance theories as a first order of business, determining that defendant was the actual killer or an active participant in the murder. Although the inadequacy of proof of felony murder was a factual matter that the jury was presumed to be "fully equipped to detect" (People v. Guiton, supra, 4 Cal.4th at p. 1129), such detection was rendered extremely difficult here because the inadequacy involved the more subtle question of accomplice corroboration of the uncharged crime of attempted robbery rather than the murder itself. As such, the record affirmatively demonstrates a reasonable probability that the jury found defendant guilty of first degree murder based solely on an insufficient felony-murder theory. The verdict must therefore be reversed.