What is the test for diminished capacity in a criminal case?

Krenwinkel asks us to determine that the specific intent requisite to the crimes charged was negated by the showing of peer pressure alone. The evidence that a party is a follower does not, however, translate itself into a prima facie showing of diminished capacity. We find no evidence in the record and know of no authority to support that proposition. The trial court's rejection of the tendered instruction was proper. (People v. Carr (1972) 8 Cal.3d 287, 294--295, 104 Cal.Rptr. 705, 502 P.2d 513.)

The record is devoid of any evidence that any appellant suffered from undisputed mental illness or from incapacity to maturely and meaningfully reflect upon the gravity of contemplated acts. (People v. Wolff (1964) 61 Cal.2d 795, 821, 40 Cal.Rptr. 271, 394 P.2d 959.) No medical or other expert testimony was offered as to a mental disease or defect of any appellant (People v. Henderson (1963) 60 Cal.2d 482, 488--489, 35 Cal.Rptr. 77, 386 P.2d 677.) Plainly put, appellants cannot point to any evidence compelling a diminished capacity instruction.