What is the current state of the law on jury instruction in a sexual assault case?

if they wish. (See People v. McDonald (1984) 37 Cal.3d 351, 369; Perry v. New Hampshire (2012) 565 U.S. ___, ___-___ [132 S.Ct. 716, 728-730].) But the parties' evidence and arguments do not obviate the need for a proper jury instruction. In light of developments in scientific research and recent case law, there is a substantial question whether it is proper for trial courts to instruct that witness certainty is a factor bearing on the accuracy of an identification that juries should consider.