## Facts

- A child was born out of wedlock in 1999 while the mother was in a relationship with Powers.
- At the child’s birth, the mother and Powers executed a statutory acknowledgment of parentage, and Powers acted as the child’s father.
- After the relationship ended, the mother and Powers entered a consent custody order granting joint legal and physical custody.
- In 2004, DNA testing established that Sinicropi, not Powers, was the biological father.
- Powers later filed a custody action seeking sole custody; the trial court entered an ex parte order granting Powers temporary sole custody pending an evidentiary hearing.
- The mother sought to dismiss Powers’s custody action and to revoke the acknowledgment, arguing biological paternity defeated Powers’s status; the trial court denied relief, relying in part on res judicata and collateral estoppel arising from prior custody proceedings.
- Sinicropi filed a paternity action under the Paternity Act, and the trial court entered an order of filiation naming Sinicropi the father while leaving the acknowledgment intact.
- The trial court effectively treated the child as having two legally recognized fathers (Powers by acknowledgment and Sinicropi by filiation), awarded Powers sole physical custody, granted the mother parenting time, and ordered both the mother and Sinicropi to pay support.
- All parties appealed.

## Issues

1. Whether a court may enter an order of filiation under the Paternity Act when a valid acknowledgment of parentage exists and has not been revoked.
2. Whether Michigan law permits a child to have two simultaneous “natural and legal” fathers through an unrevoked acknowledgment and a later filiation order.
3. Whether challenges to an acknowledgment are barred by res judicata or collateral estoppel based on prior custody orders, and what standard governs revocation.

## Decision

- The court held that an order of filiation may not be entered under the Paternity Act when a proper acknowledgment of parentage has been executed and remains unrevoked.
- The court held the trial court erred by recognizing two concurrent legal fathers for the same child.
- The court vacated the order of filiation entered in Sinicropi’s favor.
- The court remanded for the trial court to determine whether revocation of the acknowledgment is supported by clear and convincing evidence and warranted under the equities of the case.

## Legal Principles

- A valid, unrevoked acknowledgment of parentage legally establishes paternity and confers “natural and legal father” status on the signatory, including related custody and support rights and obligations.
- The Paternity Act cannot be used to create a second legal father while an acknowledgment remains in force; the statutory schemes must be applied to avoid conflicting legal paternity determinations.
- Biological paternity proven by DNA testing does not, by itself, displace an unrevoked acknowledgment; the proper mechanism is statutory revocation of the acknowledgment.
- Revocation of an acknowledgment requires application of the statutory standard, including clear and convincing evidence and consideration of the equities of the case.
- Res judicata and collateral estoppel based on prior custody orders do not eliminate the statutory revocation process for an acknowledgment of parentage.

## Conclusion

The court rejected a dual-legal-father outcome, holding that an unrevoked acknowledgment of parentage precludes a later filiation order under the Paternity Act, vacating the biological father’s filiation order and requiring the trial court on remand to decide revocation under the clear-and-convincing-evidence standard and equitable considerations.


Sinicropi v. Mazurek, 729 N.W.2d 256 (Mich. Ct. App. 2006)