D.M. v. V.B., 87 A.3d 323

Appellant (D.M.) sought court-ordered DNA testing to disestablish paternity of three children: A.M., G.W., and D.R.M.; the trial court denied the petition and D.M. appealed.
In 2000–2002 Appellant obtained legal custody of A.M. and G.W. (A.M. as custodian posing as father to expedite custody; G.W.’s biological parents’ rights were terminated) and later fathered D.R.M. during a relationship with Appellee; parties married and later separated.
In 2011 Appellee filed for child support; on June 2, 2011 Appellant signed an Acknowledgment of Paternity for A.M. and D.R.M., waiving genetic testing and trial rights; a support order was entered and later modified by an agreed order (October 7, 2011) reducing support; Appellant did not appeal.
Appellant later petitioned (Jan. 2013) to determine paternity, alleging fraud/deception regarding D.R.M. and claiming he is not the biological father; Appellee pleaded estoppel and collateral estoppel.
The trial court held Appellant is precluded from disputing paternity of A.M. and D.R.M. by collateral estoppel and paternity-by-estoppel principles; it found G.W. was never adjudicated as Appellant’s child and he is undisputedly her grandfather, but nevertheless denied testing as unnecessary.

Issue	Appellant's Argument	Appellee's Argument	Held
Whether collateral estoppel bars relitigation of paternity for A.M. and D.R.M.	Appellant sought DNA testing to disprove biological paternity and relieve support obligations.	Appellee argued the prior support order and Appellant’s signed acknowledgment conclusively adjudicated paternity; no timely appeal was taken.	Court: Held collateral estoppel applies to A.M. and D.R.M.; Appellant is precluded from relitigating paternity.
Whether collateral estoppel bars relitigation of paternity for G.W.	Appellant sought testing as to G.W. too.	Appellee argued estoppel generally; trial court treated all three similarly.	Court: Reversed for G.W. on collateral estoppel grounds — record shows no acknowledgment or order adjudicating Appellant as G.W.’s father (he is her grandfather).
Whether paternity-by-estoppel prevents disavowal as to G.W.	Appellant: can disestablish parentage; testing warranted.	Appellee: Appellant held child out / acted as parent so estoppel applies.	Court: Paternity-by-estoppel inapplicable to G.W. (Appellant never held himself out as her father); but testing denied as pointless because facts show undisputedly he is the grandfather.

Freedman v. McCandless, 654 A.2d 529 (Pa. 1995) (where estoppel applies, blood tests may be irrelevant)
McConnell v. Berkheimer, 781 A.2d 206 (Pa. Super. 2001) (support order conclusively adjudicates paternity absent timely appeal; estoppel prevents later challenge)
Schultz v. Connelly, 548 A.2d 294 (Pa. Super. 1988) (fraud or mutual mistake can excuse conclusiveness of support order)
K.E.M. v. P.C.S., 38 A.3d 798 (Pa. 2012) (paternity-by-estoppel remains viable but applies only where, on a developed record, it is in the child’s best interest)
T.E.B. v. C.A.B., 74 A.3d 170 (Pa. Super. 2013) (standard of review for paternity determinations and discussion of paternity-by-estoppel)