So, this actually sounds pretty cool. Could do a thing where the people being killed have a hidden message coded into their DNA. Like launch codes for nukes or something, and certain organizations are interested in getting it due to its inherit value. After all, weapons are the thing that people kill for. 

Or heck, it could be that the people all worked for a firm, with a vault that was never meant to be opened, so their DNA holds part of the codes? Or one guy does and the others are kind of designed to be decoys?