


Rosenthal sat in one of the parked trucks in Midtown Manhattan, as a passing driver shouted a question. The truck’s arrival often signaled to employees that a random drug test was imminent. “I put this big cup of pee on the side of the truck,” he said. He bought an RV and refocused his business on drug testing for employers. Rosenthal said he had worked in health care marketing for years before having what he described as a big blowup with an employer in 2010. It turns out the man behind the “Who’s your daddy?” truck is more Oprah than Maury. It is one, he says, that offers a unique vantage point from which to look into questions of identity and ethnicity that go to the heart of who we are as a city, and as people. Rosenthal envisioned when he was growing up in New Jersey. He has told others they were the fathers of children they never knew they had. He has told men that the children they raised were not biologically their own. Over the years, he said, he has brought long-lost siblings together and told others that they were not, in fact, related.
