Appeal from the Circuit Court of Cook County. Honorable Rene Goier, Judge Presiding.
The Honorable Justice Buckley delivered the opinion of the court: Campbell, P.j. and O'connor, Jr., J., concur.*
The opinion of the court was delivered by: Buckley
The Honorable Justice BUCKLEY delivered the opinion of the court:
Plaintiff, Bonnie Franson, on behalf of her minor child, Elizabeth Franson, filed a paternity suit against defendant, Philip Micelli. Following trial, the jury returned a verdict of paternity. On appeal, defendant contends that he is entitled to a new trial in light of the improper admittance of DNA probability evidence because: (1) the methodology by which DNA probability evidence is derived has not been generally accepted in the scientific community; (2) plaintiff failed to meet the burden of demonstrating the adequacy of the data base where the evidence did not show that the sampling was truly random, sufficiently large, and inclusive of individuals from defendant's ethnic and geographic background; and (3) the statistical probability evidence was not a proper subject of expert opinion because it relieved the jury of its duty to find the ultimate facts and unduly prejudiced defendant.
Plaintiff testified that defendant was the father of her child. Defendant denied the allegation. Defendant filed a motion in limine to bar DNA evidence from being admitted at trial. The trial court held an evidentiary hearing and concluded that the DNA evidence satisfied the Frye test (Frye v. United States (D.C. Cir. 1923), 54 App. D.C. 46, 293 F. 1013) governing the admissibility of novel scientific evidence and allowed plaintiff to present expert testimony at trial on the issue. The DNA identification process consists of the following components:
(1) Extraction: DNA is removed from the specimen and "washed" with an organic solvent.
(2) Fragmentation: The extracted DNA chain is then cut into fragments at specific sites by mixing it with a restriction enzyme.
(3) Gel Electrophoresis: The DNA is placed in a gel to which an electrical current is applied, causing separation of the fragments into bands according to their length.
(4) Southern Blotting: The DNA bands are transferred to a nylon membrane while retaining the same positions they previously occupied on the gel. The double-stranded bands are then treated with a chemical that causes them to separate into single strands.
(5) Hybridization: Genetic probes (DNA clones) are applied, which bind to a specific, complimentary DNA sequence on the membrane; the excess probe is then washed off.
(6) Autoradiography: The membrane is exposed to an X-ray film and developed so that the DNA banding patterns and their lengths can be visualized. Finally, the autoradiography is interpreted by comparing the DNA print to another DNA sample to determine if they match the band length.
DNA strands are double stranded and every person receives 50% of his or her genes from each parent. Therefore, one strand represents the DNA fragment which the person inherited from the mother and the other strand represents the DNA fragment inherited from the father. In paternity cases, DNA specimens from the child, mother and alleged father are placed next to each other. The child's maternal DNA strand is first identified by matching it with the mother's DNA. If the alleged father's sample does not contain a strand which matches the child's DNA, then the alleged father is not the father of the child. If a strand from the alleged father's DNA does match, he is not excluded.
If DNA strands match, then a paternity index is calculated for the particular locus (i.e., each match.) The paternity index is a function of comparing the likelihood of obtaining the child's genotype from the mother and the alleged father to the likelihood of obtaining a child of the same genotype from mating the mother with a random man in the appropriate population. This calculation is determined for each probe. A cumulative paternity index is then calculated by multiplying the results of each individual calculation for each probe. This is called the "product rule." This cumulative paternity index allows the tester to determine the statistical probability that a randomly chosen man from the appropriate population contributed the DNA.
In this case, the tests were conducted by Rick Staub, the associate director of paternity analysis, at Genetic Design. Genetic Design maintains DNA frequency data bases composed solely of males tested by Genetic Design and which it uses as representative samples of the representative populations. Genetic Designs' gene frequency tables are divided by race. The ...