There's enough DNA registered to find almost literally anyone in the US that way now. It's how they caught the golden state killer. A partial DNA match will narrow down 350,000,000 people to less than 100. Then it's just a matter of gettin' a box of jelly donuts and gettin' down to some good old fashioned police work with a game of Guess Who.
If you're related to anyone that has done a DNA test ever, you're already in the system.