Genetic Testing as the Exclusive Rebuttal to the Presumption of Paternity under 23 Pa.C.S. § 5104

Introduction

Sitler v. Jones, 2025 WL ___ (Pa. Apr. 25, 2025), presented the Supreme Court of Pennsylvania with a challenge to decades-old common-law authority that treated the presumption of paternity in an intact marriage as irrebuttable. Steven M. Sitler (appellant), an asserted biological father, sued for custody of his newborn and moved for genetic testing to establish his biological parentage. The trial court denied testing on the grounds of both the marital presumption and paternity by estoppel. The Superior Court affirmed as to the irrebuttable presumption but did not reach estoppel. The Supreme Court reversed in part, overruling the irrebuttable presumption, but stopped short of fully enforcing the Legislature’s directive in 23 Pa.C.S. § 5104 (the “Uniform Act on Blood Tests to Determine Paternity”), substituting a multi-factor threshold test in its place. Justice Donohue concurred in overruling the irrebuttable presumption but dissented on judicially grafting obstacles to scientific proof of biological parentage.

Summary of the Judgment

The Majority held that:

The old common-law rule that the presumption of paternity in a valid marriage is irrebuttable must be overruled.
Section 5104(g) of Title 23 declares that definitive scientific testing “overcomes” the marital presumption—but modern practice, judicial precedent, and the child’s best interests require a careful, two-step inquiry before testing is ordered.
They announced a new multi-factor test: to compel DNA testing a putative father must show (1) a reasonable possibility he is the biological father, and (2) that testing serves the child’s best interests (with due weight to the spouses’ interests).
The case was remanded for application of that new test, and the Superior Court was directed to address the trial court’s independent finding of paternity by estoppel.

Justice Donohue (joined by Justice Mundy in part) agreed that the irrebuttable presumption should fall, but dissented from adding a judicial threshold test. She would have simply enforced the Legislature’s clear mandate in 23 Pa.C.S. § 5104: if a putative father requests genetic testing promptly and a credible basis for paternity exists, the court “shall” order it; results conclusively rebut or uphold the presumption. Additional policy-based inquiries, she argued, belong to the legislative branch, not the judiciary.

Analysis

1. Precedents Cited

Dennison v. Page, 29 Pa. 420 (1857) – Articulated the common-law presumption that a child born in wedlock is the husband’s offspring.
Cairgle v. American Radiator, 77 A.2d 439 (Pa. 1951) – Defined the presumption’s strength and grounds for rebuttal (non-access or impotence).
Commonwealth ex rel. O’Brien v. O’Brien, 136 A.2d 451 (Pa. 1957) – Narrowly read early blood-test statutes to exclude testing in support proceedings where the presumption of legitimacy already applied.
John M. v. Paula T., 571 A.2d 1380 (Pa. 1990) – Held that the blood-test statute did not permit a putative father to compel testing of the marital husband; Chief Justice Nix’s unanimous concurrence declared the marital presumption absolute “notwithstanding” the statute (dicta).
Jones v. Trojak, 634 A.2d 201 (Pa. 1993) – Imposed threshold requirements (“rebut permission” and “no estoppel”) before trial courts could order blood tests under § 5104.
Strauser v. Stahr, 726 A.2d 1052 (Pa. 1999) – Rejected HLA testing where the presumption stood and estoppel applied; dissent argued this conflicted with § 5104’s clear command.
B.C. v. C.P., 310 A.3d 721 (Pa. 2024) – Addressed modern statutory context; Justice Wecht’s concurrence lamented that § 5104 still speaks only of “blood tests” when DNA marker analysis is the norm.

2. Legal Reasoning

The Majority undertook a two-stage approach:

Overrule the irrebuttable marital presumption—acknowledging the Legislature’s 1961 adoption (and later recodifications) of the Uniform Act on Blood Tests, which expressly declares that conclusive scientific tests “overcome” the presumption of paternity.
In lieu of fully implementing § 5104’s “shall order” language, devise a judicially created threshold test requiring a putative father to show (a) a reasonable possibility that DNA testing would confirm biological paternity, and (b) that ordering testing serves the child’s best interests (weighing all familial interests).

Justice Donohue’s dissent argued that this two-step judicial filter directly contradicts the statutory text and the General Assembly’s explicit policy choice. She would apply § 5104(c)’s mandatory language: once a timely motion is made by a party with a credible basis for paternity, the court “shall order” scientific testing; the results then govern the presumption under § 5104(g).

3. Impact on Future Cases and the Law

Courts will now apply the Majority’s two-factor test before ordering DNA testing in intact marriages, creating additional litigation over “reasonable possibility” and “best interests” inquiries.
The decision blurs the line between biological parentage and custody rights, potentially requiring custodial analyses at the paternity-testing stage.
Legislators may be prompted to amend § 5104—either reinforcing a mandatory testing regime or codifying the court’s threshold test—to end prolonged debates over statutory interpretation.
The ruling may affect custody, support, and adoption proceedings by layering new procedural hurdles before definitive genetic proof is obtained.

Complex Concepts Simplified

Presumption of Paternity: Under common law, a child born during a valid marriage is presumed to be the husband’s child—originally to protect legitimacy and family stability.

Uniform Act on Blood Tests (23 Pa.C.S. § 5104): A statute adopted in 1961 and recodified in 1990 that:

Applies to any civil case where paternity is relevant.
Requires courts to order scientific tests (formerly blood typing, now DNA) when paternity is at issue and a timely motion is made.
Declares the presumption of paternity “overcome” if experts agree the husband is not the biological father.

Paternity by Estoppel: A doctrine preventing a party from denying paternity when he has previously represented to the child, mother, or community that he is the child’s father, and the child has relied on that representation.

Conclusion

Sitler v. Jones marks a pivotal moment in Pennsylvania paternity law: the Supreme Court overturned the irrebuttable marital presumption but stopped short of fully enforcing the Legislature’s clear directive in 23 Pa.C.S. § 5104. Instead, it inserted a judicial threshold test before DNA testing may proceed in intact marriages. The dissent urges strict adherence to the statute’s mandatory language, arguing that additional judicially-crafted obstacles conflict with the Legislature’s policy to let conclusive scientific evidence govern parentage. The decision sets the stage for further legislative action or eventual reconsideration by the courts to reconcile statutory text with long-standing public policy favoring biological verity.