What is the test for making a finding of guilty under former CALCRIM No. 400?

In sum, we conclude that, based on the record before us in this case, there was no reasonable likelihood the jurors would have understood the "equally guilty" language in former CALCRIM No. 400 to allow them to base defendant's liability for first degree murder on the mental state of the actual shooter, rather than on defendant's own mental state in aiding and abetting the killing. (People v. Clair (1992) 2 Cal.4th 629, 663, 7 Cal.Rptr.2d 564, 828 P.2d 705 ; Estelle v. McGuire (1991) 502 U.S. 62, 72, 112 S.Ct. 475, 116 L.Ed.2d 385.)

4. Prior-murder special circumstance finding based on a murder that occurred after the capital offense