Generally, this only comes up after the mother has decided she no longer wants the child’s presumed father in her and the child’s life.  Without regard to how the child and presumed father may have bonded, the mother seeks to remove the presumed father by requesting a DNA test.
Under the Uniform Parentage Act (Fam. C. §7600 et seq.) paternity is rebuttably presumed in favor of a man who meets any of six specified conditions.  In the above referenced situation, Family Code section 7611 (d) applies:
•    When a man receives a child into his home and openly holds out the child as his natural child, he is then presumed to be the natural father of said child.
•     This presumption may be rebutted in an appropriate action only by clear and convincing evidence.
A clear declaration of receiving a child into your home and openly holding the child out to be your natural child, include one or more of the following:
•    Participating in the birth of the child;
•    Agreeing to place your name on the birth certificate;
•    Signing a Voluntary Declaration of Paternity;
•    Ccaring for and providing for the child after birth; and/or
•    Introducing the child to friends and family as your child.
There is no specific duration for how long these acts must have occurred, the test is the clear declaration of the nature of the relationship between father and child.  Once the presumed father proves these actions to the court, he triggers the presumption of being named the natural father.
A DNA test showing that the presumed father is not the biological father does not automatically constitute “clear and convincing evidence” defeating the presumption. Family Code section 7612 (a) states that the presumption of natural father may only be defeated in appropriate actions.  The court has the discretion to allow or disallow an action to defeat the presumption.  Thus, social relationships may “trump” genetics.  Especially, if defeating the presumed fatherhood with an admission of a blood/genetic test proof of non-paternity would effectively leave the child fatherless.
Consequently, it is imperative if you are facing this legally complicated situation to hire an attorney in Los Angeles as soon as possible. The experienced family law attorneys at Wallin & Klarich are available to help you in such a complex case. If you or a loved one needs help with a matter such as this, please call Wallin & Klarich today.