The feds think Arlington’s Bathroom Bank Robber may have had help from the inside — a teller.  Three weeks ago, a robber hid out in the men’s room of Texas Trust Credit Union in Arlington.  After closing time, he emerged and herded frightened tellers into the vault, escaping with more than 180-thousand dollars, a far larger haul than most bank robberies yield.  After looking at surveillance video, police and FBI agents grew suspicious of a teller who stayed beyond his normal shift and who was seen texting just before the stick-up.  Checking Kyle Lightner’s phone records, they found he had been exchanging text messages with Tyce Von Franklin who was arrested just four hours later.  Now, the feds are looking into another bank heist where Franklin and Lightner may have been in cahoots.  That one was at a Compass Bank where Lightner also worked.  He appeared to be taken hostage and force into a vault by a man whose description closely matches Franklin.  Another large sum, nearly 150-thousand, was taken.