Just want to put this here for anyone else having trouble finding or getting credit for killing a Beharen Security Droid as part of the "Data Mining" achievement. There doesn't seem to be a good guide for this anywhere, so I'd like to post what I've learned so far for others to reference:
*Beharan Security Droids are normal mobs usually in a group of other normal mobs.
They seem to spawn in the fenced up areas of Corellia-> Labor Valley -> Western area.
*Known sightings: I've seen them spawn at 3 locations (-3446, -1865), (-3574, -1802) and (-3780, -2115) (see map below.)
*Beharen Droids don't follow normal respawn rules. Sometimes the groups wont respawn for hours. Perhaps killing the surrounding enemies will affect the respawn rate, perhaps it won't.
*I had to kill the Beharan Security Droid on a pub toon to get credit. I wasn't getting credit on my imp toon.
*Someone else in my party who got the first hit and the kill on the Beharen Security Droid didn't get credit for it; but I did for some reason.
*It just seems all around buggy.
Other Beharan-type droids that can spawn in the same locations instead of the Security droids are:
*Beharan Striker Droid (Gold)
*Beharan Heavy Droid (Silver)
*Beharan Assault Droid (Normal)
It's best to clear these other droids whenever you see them so the Security droids have a chance of spawning next time.
Map of all droid Locations: https://imgur.com/wLIfUFJ
Location 1: https://imgur.com/QIBklgB
Location 2: https://imgur.com/qVpJduP
Location 3: https://imgur.com/kCicfwJ