Kammer v. Young

BISHOP, Judge.

A Baltimore City jury found appellant, Thomas Robert Kammer, to be the father of the child of Christine J. Young, appellee. From the decree of the circuit court based on this verdict, Kammer appeals.

FACTS

Appellee gave birth to a child on May 24, 1982. She alleged that appellant was the only man with whom she had had sexual intercourse in the year immediately preceding the child's birth. Appellant responded that his sexual relations with appellee had ended more than 15 months before the birth.

The court admitted into evidence, over objection, the results of the blood tests of appellant, appellee and the child, obtained in accordance with MD.FAM.LAW CODE ANN. Section 5-1029. Additional facts will be given in the course of the discussion of the issues.

I.

Admissibility of Blood Test Evidence

(a)

Admission of Opinion Evidence Concerning the Interpretation of the Blood Tests

In his attack on the admissibility of the interpretation of the blood tests, appellant claims that:

(1) the expert witnesses appellee called at trial were not qualified to perform statistical analysis, to interpret the results or to express an opinion on the ultimate issue of the “statistical probability” of the appellant's paternity; and

(2) the number presented to the jury was predicated upon a scientifically invalid formula and was not a competent “statistical probability of paternity” thereby rendering the laboratory report inadmissible at trial.

Appellant also asks that we reconsider our decision in Haines v. Shanholtz . . . in which we held that by virtue of legislative enactment, blood test results which meet certain threshold requirements are admissible. We decline to do so.

This controversy is governed by § 5-1029 of the MD.FAM.LAW CODE ANN. (1984) which provides in pertinent part:

5-1029. Blood tests.

(a) In general.-On the motion of a party to the proceeding or on its own motion, the court shall order the mother, child, and alleged father to submit to blood tests to determine whether the alleged father can be excluded as being the father of the child.
(b) Approved laboratory required.-The blood tests shall be made in a laboratory selected by the court from a list of laboratories provided by the Administration.

(c) Form of results.-The laboratory shall report the results of each blood test in writing and in the form the court requires.

(d) Copies of results. A copy of the results of each blood test shall be provided to the parties or their counsel in the manner that the court directs.

(e) Results as evidence.-(1) The results of each blood test shall be received in evidence if:

(i) definite exclusion is established; or

(ii) the testing is sufficiently extensive to exclude 97.3% of alleged fathers who are not biological fathers, and the statistical probability of the alleged father's paternity is at least 97.3%.

(2) A laboratory report is prima facie evidence of the results of a blood test.

(3) If a laboratory report is admitted in evidence, the laboratory technician who made the test is subject to cross-examination by any party to the proceeding.

We begin our analysis of the applicability of this section to the appellant's claims by setting out the following facts which are undisputed by the parties:

(1) Appellee's witnesses are employed by an approved blood testing laboratory and are qualified in the field of paternity testing, but are not trained statisticians. Appellant's witness is a trained statistician and although he is not employed by a blood testing laboratory he does consult, as part of his employment, with the paternity testing laboratory at Johns Hopkins Hospital.

(2) The blood tests were performed by an approved laboratory and the testing was done for blood group markers in seven different systems, six in the red cell laboratory and for HLA [Footnote 2] in the white cell laboratory.

=====FOOTNOTE 2=====

HLA is the abbreviation for human leucocyte antigen.

=====Footnote End=====

(3) The combination of the HLA and red cell tests is sufficiently extensive to exclude more than “97.3% of alleged fathers who are not biological fathers”.

(4) The “paternity index” [Footnote 3] in this case is 460 to 1, i.e. it is 460 times more likely that appellant could produce the single sperm carrying the necessary genetic information than a random man in the population.

=====FOOTNOTE 3=====

A paternity index is a ratio which expresses the odds that the accused is the father of the child based on his chance of producing a sperm that carries all the necessary genetic information in conjunction with the mother's genetic information as compared to finding such a sperm in the random population.

=====Footnote End=====

(5) The prior probability [Footnote 4] used by the laboratory in converting the paternity index to a percentage was .5, and that number is the standard used for such tests.

=====FOOTNOTE 4=====

Prior probability is expressed as a number, in the form of a percentage, which represents the accumulated non-genetic evidence that tends to indicate the accused man's paternity.

=====Footnote End=====

(6) Using a prior probability of .5, the percentage which results from application of Bayes' Theorem [Footnote 5] to the paternity index of 460 to 1 is 99.78%.

=====FOOTNOTE 5=====

Bayes' Theorem is a mathematical technique accepted in the blood testing field for calculating conditional probabilities. . .

=====Footnote End=====

(b)

Admission of the Blood Test as a Violation of Due Process

Appellant contends that even if appellee properly complied with the blood test statute, the admission of any opinion evidence concerning the father's alleged “statistical probability” of paternity violates the due process provisions of the United States and Maryland Constitutions. He also claims that apart from the due process violation, the introduction of statistical and mathematical evidence on the ultimate issue before the jury effectively deprived him of a fair and impartial trial by jury as guaranteed by Article 23 of the Maryland Declaration of Rights.

Appellant's due process challenge is actually a two-pronged attack. He asks whether: (1) due process of law permits a paternity index to be converted to a statistical probability of paternity through the use of Bayes' Theorem with an assigned prior probability; and (2) the limited reference population used in this case [Footnote 12] can be used to compute the “paternity index” used in the equation.

=====FOOTNOTE 12=====

Appellant's blood markers were compared against a gene frequency chart which shows how often his specific gene pattern arose in the United States in tests of 12,000 persons of his same race.

=====Footnote End=====

Once appellant's paternity index has been calculated, it must then be converted to a statistical probability in order to determine whether it meets the 97.3% benchmark for admissibility set forth in § 5-1029(e)(1)(ii). The mathematical equation used in making this transformation is Bayes' Theorem, a basic formula of probability theory. It is expressed as follows:

1
----------------
P(F/M) = (1-f) + (f/P(F))

where

P(M/not-F)
----------
f =
P(M/F)

In this formula, P(F) represents the prior probability and it is factored into the equation in order to account for the non-genetic evidence of the accused man's paternity.

Ideally, the prior probability should reflect an assessment of all the relevant non-genetic evidence in each individual case and should take into consideration such factors as the accused man's opportunity for access to the child's mother during the period of conception, the evidence linking the child's mother to other men during that time period and the credibility of the witnesses. In the case sub judice, however, an assumed prior probability of fifty percent (.5) was used in converting appellant's paternity index to a statistical probability. He contends that this was a violation of his due process rights. We disagree.

Appellant claims that the methodology employed by all of appellee's experts assumes a fact not in evidence (the prior probability) and it is therefore scientifically inaccurate and invalid. We disagree. The evidence presented at trial makes plain that within the relevant community of blood testers, the paternity probability calculations in the present case were based upon scientific methods, accepted world-wide, which incorporate both Bayes' Theorem and the .5 prior probability. [Footnote 14] All of the experts who testified at trial agreed that the paternity index, representing only the purely genetic evidence (the HLA and the red cell tests), was 460 to 1. Furthermore, using Bayes' Theorem and a prior probability of .5, all of the experts (including appellant's expert Dr. Chase) calculated the same probability percentage of 99.78%. The mathematical basis for the .5 figure was explained by Dr. Chase in the following manner:

====FOOTNOTE 14=====

Because the use of the .5 as a basis for prior probability meets the requirement of general acceptance in the relevant community, it satisfies the test for admission of scientific evidence set out in Frye v. United States, 293 F. 1013 (D.C.Cir.1923) and adopted by the Court of Appeals in Reed v. State, 283 Md. 374, 391 A.2d 364 (1978).

=====Footnote End=====

“If you know nothing about a set of possibilities then the principle of insufficient reason says you are entitled to assign equal prior probability to those alternatives. [T]hat's what's used to get this .5. This .5 comes from a principle that says we don't know whether he was the father or somebody else was the father. So we are going to split the probability fifty-fifty between the two possibilities. We are going to load him with 50 percent of it and give the other percent to all the other men.”

When calculating a statistical probability of paternity, the blood testing laboratory does not have before it any of the individualized non-genetic evidence, and it therefore uses a standard figure (.5) whenever it makes its calculations. This fact neither renders the methodology “scientifically invalid” nor does it deny appellant an opportunity to present the non-genetic evidence. If the laboratory's calculations meet the prerequisites for admissibility set forth in § 5-1029(e)(1)(ii) the blood test evidence is admitted, but it is neither conclusive nor does it create a presumption, it is merely one piece of evidence that is put before the jury. Appellant was free to, and in fact did, put on non-genetic evidence which not only disputed generally his paternity but, in effect, was an attack upon the use of the .5 prior probability figure. This allowed him an opportunity to counterbalance appellee's introduction of the blood test results and the prior probability on which they were based and served to protect his due process rights.

We decline to respond to appellant's second contention, regarding the sufficiency of the reference population used in determining the paternity index, on the basis of Maryland Rule 1031 c 5 and this Court's holding in Van Meter v. State . . . Nowhere in the record or in the briefs does appellant offer any argument in support of his claim that the reference population used was inadequate. In his brief, appellant merely states:

The record also raises a serious question about whether the “reference population” used by the Baltimore RH Laboratory, consisting in total of a mere 12,000 persons, is legally sufficient upon which to predicate the appellant's paternity index” of 460:1. Appellant respectfully submits that there is no legally sufficient evidence to support the assumption made by the Baltimore RH Laboratory that this data base is adequate to use with Bayes' Theorem to extrapolate the statistical “plausibilities” made in this case, or that it is a proper “reference population” at all.

Yet, he offers no proof to support his conclusion. From this bald assertion, appellant leaps to the conclusion that his due process rights have been violated because of the size of the reference population used. Appellant, by failing to include in his brief any argument to support his claim that the reference population was insufficient, provides us with nothing to consider as a basis for his contention.

Appellant does provide some argument on his right to a fair and impartial jury trial claim; however, we are not persuaded. He argues that the “statistical approach to the case distracted the jurors from weighing the evidence and determining the ultimate credibility of the plaintiff and defendant ...” and that the jury “unquestionably was overwhelmed” by the testimony that the “plausibility” of the appellant's paternity was “99.78%”, and therefore he was denied a right to a fair and impartial trial. The “statistical approach” to this case is no different from any other paternity case, and it is precisely what is required by the statute. The fact that the percentage obtained, 99.78%, may be perceived as “overwhelming” because of the extent to which it reaches 100% conclusiveness does not in any way prevent appellant from receiving a fair trial. The “statistical probability of paternity” required by the statute comprises only one part of the evidence that is put before the jury concerning the alleged father's probable paternity. It is not the only evidence and it does not create an irrebuttable presumption of paternity. Appellant was allowed to put on evidence in support of his claim that he is not the child's father. All of the evidence went to the jury and there is no evidentiary support for his claim that the jurors improperly relied on the statistical probability as being dispositive of the issue.

JUDGMENT AFFIRMED; COSTS TO BE PAID BY APPELLANT.