Biological fathers in California have a legal right to access to their children, but they might need to take some steps to establish that right. First, it may be necessary to establish paternity. While this may simply involve signing an acknowledgement of paternity, in disputed cases, it could involve DNA testing.
Parents will need to negotiate a parenting agreement that spells out when the child will spend time with each of them. This can be done before the legal process is underway. If parents cannot reach an agreement, they may need to go to court and have a judge decide. Even if parents do not have to go to court to make the agreement, the advantage of submitting it to court for approval is that it becomes legally binding. This means that the agreement can be enforced if either parent violates it.
Courts generally work from the assumption that it is in the best interests of the child to have contact with both parents. However, if one parent is a danger to the child because of issues such as abuse, courts may block visitation. It would also be unusual for an unmarried father to be granted sole custody of a child unless he is already the primary caregiver or the mother is found to be unfit in some way.
Parents may help make this process less difficult by focusing on the best interests of the child. If they had a relationship that ended badly, they may be tempted to try to punish their former partner using the child, but they should make an effort to set those feelings aside. With their attorneys, they might be able to create guidelines around coparenting that address any major issues that either parent is concerned about.Source: FindLaw, "Child Custody and Visitation Rights for Unmarried Fathers," 10/26/2018