I'd also have to jump on the male bandwagon. As for why, if you look at the top pic you submitted, the tail doesn't really hardly taper at all after the cloaca....leaves plenty of room for hemipenes. You will, a lot of times, see much more of a taper after the cloaca on females. Question though? You have UnitedStates as where you're from, but the pic is of SanFran. Garters (T.s.tetrataenia).....they are a federally protected species in the US. Do you have some special permit to have them or something? Just curious, I'd love to be able to work with them if it were possible....but legally of course.
Roy