In re Parentage of R.R., 538 P.3d 838

R.R. was conceived while Mother was married to T.R.; R.R. was born during that marriage and T.R. signed the birth certificate.
Mother had an extramarital relationship with T.T.; a private DNA test showed a 99.9% probability that T.T. is R.R.’s biological father.
T.T. filed a paternity action seeking declaration of paternity and shared legal custody; T.R. intervened and divorce proceedings between Mother and T.R. were pending.
At the district court hearing both men had active, loving relationships with R.R.; evidence emphasized T.R.’s longer/earlier parenting role and R.R.’s close bond with his older brother (Brother).
The district court applied the Greer best‑interests factors to weigh competing statutory presumptions and found T.R.’s presumptions weightier; the Court of Appeals (unpublished) affirmed.
The Kansas Supreme Court granted review and affirmed the Court of Appeals and district court: T.R.’s presumption controlled and there was no abuse of discretion.

Issue	Plaintiff's Argument (T.T.)	Defendant's Argument (T.R.)	Held
Whether the district court misapplied the KPA burden‑shifting scheme when competing presumptions arose	Court started with marital presumption and effectively imposed a higher burden on T.T.; biology was undervalued	KPA burden shifting applies: T.T. proved initial biological presumption, T.R. raised competing presumptions, and T.T. then bore the burden to prove by preponderance that his presumption was weightier	Affirmed — court correctly applied K.S.A. 23‑2208(b)-(c); T.T. bore the burden to show his presumption was founded on the weightier policy/logic and best interests of the child
Whether the district court abused its discretion in weighing Greer best‑interest factors (including alleged judicial bias)	Court’s factual findings lacked substantial competent evidence; comments show unconscious bias favoring marital presumption	District court’s Greer findings are supported by substantial competent evidence (length of relationship, sibling bond, stability); judge expressly limited any reliance on presumption and denied bias	Affirmed — no abuse of discretion; substantial competent evidence supports findings and record does not show improper bias

Greer v. Greer, 50 Kan. App. 2d 180, 324 P.3d 310 (Kan. App. 2014) (articulates nonexclusive best‑interest factors used to weigh competing paternity presumptions)
In re M.F., 312 Kan. 322, 475 P.3d 642 (Kan. 2020) (explains KPA burden‑shifting and that ultimate burden is by preponderance when presumptions conflict)
Geer v. Eby, 309 Kan. 182, 432 P.3d 1001 (Kan. 2019) (defines substantial competent evidence standard)
Biglow v. Eidenberg, 308 Kan. 873, 424 P.3d 515 (Kan. 2018) (describes abuse of discretion framework)
In re B.D.-Y., 286 Kan. 686, 187 P.3d 594 (Kan. 2008) (appellate courts must not reweigh evidence)
Harrison v. Tauheed, 292 Kan. 663, 256 P.3d 851 (Kan. 2011) (legal questions and statutory interpretation reviewed de novo)