They are used for several reasons. First, let's begin with the most obvious:
As legal evidence for supporting children
While you can collect and test your Father's Paternity Testing Brandon without your knowledge, those results are not allowable before the court. The Father must sign a form for the chain of custody that permits the test to be legally valid, and the test laboratory should also follow specific procedures. He could call, but the court could force him to take the test. If the test is taken once the form is signed, you have legally recognized evidence that he or she is your child's Father.