People v. Guiuan
In People v. Guiuan (1998) 18 Cal.4th 558, the Supreme Court concluded CALJIC No. 3.18, addressing accomplice testimony required modification.
Prior to Guiuan, CALJIC No. 3.18 informed the jury all accomplice testimony should be viewed with caution. In Guiuan the Court ruled the instruction should be modified to tell the jury accomplice testimony, which incriminates, should be viewed with caution. ( Id. at pp. 563-570.)
The Guiuan Court did not require the instruction to distinguish between incriminating testimony and testimony exonerating the defendant.
Significantly, the Supreme Court did not require a modification of CALJIC No. 3.18 to inform the jury to view exonerating evidence without caution.