EMBED >More News Videos Authorities have charged a pair in connection with an alleged sex crime ring.

EMBED >More News Videos The women accused of working at a United Airline pilot's alleged brothel appeared in court on prostitution charges Thursday.

HOUSTON (KTRK) -- We first saw Bruce Wayne Wallis months ago, when he was initially arrested for what would become bombshell allegations: The veteran United Airlines pilot allegedly ran a sophisticated brothel ring that included dozens of women, spanning several Houston office buildings and apartments.Now search warrants uncovered by Eyewitness News shed light on how investigators unraveled the whole affair. Records show Houston police officers focused on a nondescript building at 10333 Northwest Freeway. It appeared vice officers were initially trying to bust a prostitution ring at suite 422. What they would soon uncover, would be a much wider scheme.According to the warrant, a confidential informant told investigators that there was a drop box in suite 422, where the girls placed their money every week to pay Wallis so called 'rent' money.The documents said that girls working in suite 422 were charging $100 to $200 for various sex acts.The warrant also showed that each girl got clients by having their own backpage advertisement, an independent phone number, and kept their own schedules. However, any new client would have their phone number screened by a manager.That manager was allegedly Tracie Tanner, the woman charged alongside Wallis in the prostitution ring. Documents show Tanner would allegedly check out the phone numbers to make sure the new clients were not cops.Besides confidential informants, documents show Houston Police also used recorded conversations on multiple occasions and placed tracers on the suspects' cars to make their case.Bruce Wallis is scheduled to appear in court again, next month.