Collins

I dissent. I would affirm the judgment in its entirety.

Appendix

If “Pr” represents the probability that a certain distinctive combination of characteristics, hereinafter designated “C,” will occur jointly in a random couple, then the probability that C will not occur in a random couple is (1 — Pr). Applying the product rule (see fn. 8, ante), the probability that C will occur in none of N couples chosen at random is (1 — Pr)N, so that the probability of C occurring in at least one of N random couples is [1— (1 — Pr)N].

*334 Given a particular couple selected from a random set of N, the probability of C occurring in that couple (i.e., Pr), multiplied by the probability of C occurring in none of the remaining N — 1 couples (i.e., (1 — pr)N—yields the probability that C will occur in the selected couple and in no other. Thus the probability of C occurring in any particular couple, and in that couple alone, is [ (Pr) X (1—Pr)N—•1]. Since this is true for each of the N couples, the probability that C will occur in precisely one of the N couples, without regard to which one, is [(Pr) X (1 — Pr)N—1] added N times, because the probability of the occurrence of one of several mutually…

We deal here with the novel question whether evidence of mathematical probability has been properly introduced and used by the prosecution in a criminal ease. While we discern no inherent incompatibility between the disciplines of law and mathematics and intend no general disapproval or disparagement of the latter as an auxiliary in the fact-finding processes of the former, we cannot uphold the technique employed in the instant case, As we explain in detail, infra, the testimony as to mathematical probability infected the case with fatal error and distorted the jury’s ^traditional role of determining guilt or innocence according to long-settled rules. Mathematics, a veritable sorcerer in our computerized society, while assisting the trier of fact in the . search for truth, must not cast a spell over him. We conclude that on the record before us defendant should not have had his guilt determined by the odds and that he is entitled to a new trial. We reverse the judgment.

A jury found defendant Malcolm Ricardo Collins and his wife defendant Janet Louise Collins guilty of second degree *321 robbery (Pen. Code, §§211, 211a, 1157). Malcolm appeals from the judgment of conviction.…

We deal here with the novel question whether evidence of mathematical probability has been properly introduced and used by the prosecution in a criminal case. While we discern no inherent incompatibility between the disciplines of law and mathematics and intend no general disapproval or disparagement of the latter as an auxiliary in the fact-finding processes of the former, we cannot uphold the technique employed in the instant case. [1a] As we explain in detail, infra, the testimony as to mathematical probability infected the case with fatal error and distorted the jury's traditional role of determining guilt or innocence according to long- settled rules. Mathematics, a veritable sorcerer in our computerized society, while assisting the trier of fact in the search for truth, must not cast a spell over him. We conclude that on the record before us defendant should not have had his guilt determined by the odds and that he is entitled to a new trial. We reverse the judgment.

A jury found defendant Malcolm Ricardo Collins and his wife defendant Janet Louise Collins guilty of second degree robbery (Pen. Code, 211, 211a, 1157). Malcolm appeals from the judgment of…