concurring specially.
While agreeing with Divisions 2 and 3 of the majority opinion, additional observations should be made as to Division 1.
The majority opinion points out that evidence was before the trial court that appellant had Type A blood; that based upon a saliva test, the appellant was a secreter; and that at trial an expert had indicated that 36% of the population are Type A secreters.
A police officer testified that the procedure for obtaining saliva was to require a suspect to chew on a rubber band or ice, which would generate saliva. The suspect would then spit into a plastic container, and the collected saliva would then be tested as soon as possible to determine whether it contained blood antigens. The expert explained that only a “secreter” released blood antigens in all his or her bodily fluids. This expert testimony, presented as statistical probability, along with the evidence that appellant had Type A blood and was a secreter, served to include the appellant in the reduced percentage of population that could have possibly committed the rape.
*57While matters of statistical and mathematical probability, and expert evidence, may be used, care must be observed in laying a proper foundation when estimates are used. “ ‘We hold that mathematical odds are not admissible as evidence to identify a defendant in a criminal proceeding so long as the odds are based on estimates, the validity of which have [sic] not been demonstrated.’” Graham v. State, 168 Ga. App. 23, 27 (308 SE2d 413) (1983).
When in doubt, evidence ordinarily should be admitted for consideration by the jury, yet these observations are made to emphasize the caution with which the courts should greet such presentations of statistical probability in criminal proceedings. Nevertheless, because the other, conventional evidence as to the appellant’s guilt was overwhelming in this case, I agree with the majority that the admissions of the evidence could not have contributed to the verdict.