After rewatching DS9: “Defiant”, I had a thought; to prevent transporter clones from impersonating each other, could Starfleet require, as a part of duty, that transporter clones receive slight genomic resequencing that changes no major traits but allows DNA scanners to distinguish them?
I can think of a few issues. One, would it break genetic experimentation laws even though there would be negligible changes to each transporter clone? Two, is this too sever a violation of personal liberties for the Federation to be allowed? Three, is the technology there to do this effectively in a starship’s sickbay?
It should be considered no different than scanning for errant microbes/viruses/changlings. Not to mention, there should already be a detectable difference in phase variance by merely being a body in another point in spacetime (updated info not reaching all known outposts/ships notwithstanding).