Covertly Transported-In Eggs

Time Traveling Criminals often used Freeze Dried Sperm to impregnate their victims of Rape By Impersonation, then, because they often impersonated individuals with similar appearances, they were able to covertly transport in (side-timed) instances of the fertilized eggs that made them, in order to produce replicas of themselves, apparently naturally born. Of course they murdered them and took their bodies.