I hate to break this to you but we are, as of yet, not living in a dystopian futuristic society that has every single human being's DNA information on file for public use.
It's not an "insert cheek swab sample and get a receipt that reads "biological parents - Mr. DeMayo Gregory and W÷d~hsh¶52°8hsjg¥¢÷[fjddrt" with a Google Maps pin URL to their exact location. No DNA test works like that.
DNA tests - maternity and paternity DNA tests - work more like looking at two piles of Legos assembled into two strips of long random color sequences and seeing which one of them is more similar to the photo of yet another pile of Legos in a long strip.
Congrats! It's... Your twin?
Anyway, the process for testing for paternity needs both the sample from the father AND child. Because it's not a Google search - it’s a "find the difference" game.
So even if Steven wanted to, he can't just roll up to his friendly neighborhood hospital and go "Give Me Lucrative Info On My Real Parents by Looking into my Amino Acid Curly Fries!" because even if DNA does have that information, most people's genomes aren’t attached to their legal name, phone number and bank account.
