Two different men fathered twin sisters
A man identified only as "A.S." was believed to have fathered twins but turns out he only fathered one of them. This came out in a precedent setting court case in New Jersey. Judge Sohail Mohammed ruled that the man was off the hook for child support payments to one of the twins after DNA testing determined he fathered one with 99.9 percent certainty but could absolutely not have been the father of the other.
How can this happen? It's a medical rarity. The woman released two eggs instead of one, then had sex with more than one man in the same menstrual cycle and both got her pregnant. They say in paternity cases involving twins it is only a 1 in 13,000 occurrence. This is only the third paternity case in the United States involving twins where it turned out this way and the first in the Garden State.
How common is paternity fraud? The following is from Wikipedia:
A 2005 scientific review of international published studies of paternal discrepancy found a range in incidence, around the world, from 0.8% to 30% (median 3.7%). However, as many of the studies were conducted between the 1950s and the 1980s, some numbers may not be reliable due to inaccuracies in the scientific testing methods and procedures used at the time. The latest studies, ranging in date from 1991 to 1999, quote the follow incidence rates: 4.0% (Canada), 2.8% (France), 1.4% and 1.6% (UK), and 11.8% (Mexico), 0.8% (Switzerland). These numbers suggest that the widely quoted and unsubstantiated figure of 10% of non-paternal events is an overestimate. However, this number may have been inaccurately circulated due to the following: in studies that solely looked at couples who obtained paternity testing because paternity was being disputed, there are higher levels; an incidence of 17% to 33% (median of 26.9%). Most at risk were those born to younger parents, to unmarried couples and those of lower socio-economic status, or from certain cultural groups."
Think about it. A mother always knows she is the mother. A father, despite the love and the trust, ultimately only knows what he is told. Unless he has his partner under 24 hour fail proof surveillance, a father goes on trust. Considering the advances in and affordability of modern day paternity testing, how would you feel about it becoming law that all babies born must have a paternity test before putting the father's name on the birth certificate? In cases where the mother is honest enough to say she's not sure, father unknown can be placed on the certificate.
This wouldn't just stop the heartbreak of finding out a child you've been raising for three, five, ten years isn't yours. It would also stop the financial fraud of supporting a child that was never yours in the first place. There's no current legislative initiative that I'm aware of calling for mandatory paternity testing, but should there be?