There are legal distinctions between "alleged" fathers (possible biological fathers) and "presumed" fathers, those who, after the child is born, receive the child into their home and hold themselves out to the world as the child's father. There are even cases in which, because of a long history of acting as the father and supporting the child, the man can be legally declared to be the father even if HLA blood tests prove that he is not the biological father, and he can be ordered to continue paying child support, or he can use this "parenthood by estoppel" argument to obtain visitation and custody rights, or the child can use it to be determined to be an "heir" for inheritance purposes.
Even this list of situations is no means all-inclusive, and life is often stranger than fiction, where creative lawyering and aggressive representation is urgently needed by someone involved in a paternity-related matter. With my rich and varied experience and background, I am the man for the job, regardless of which side you are on, or which party you are.