Immigration and Customs Enforcement quietly announced last week that it is investigating alleged sexual assault at a privately run immigrant detention center in Texas. The incident is the latest in a string of sexual assault charges and convictions at Texas detention centers. The alleged perpetrator has been fired for charges of numerous instances of sexual assault. In one case, the officer is said to have propositioned a woman for sex as she rode on a bus from the detention center to the airport where she was to be deported. According to one advocate, the women was only able to report the incident by telling a security officer at the airport as she was headed to the plane to be deported. "We understand that this employee was able to commit these alleged crimes because ICE-mandated transport policies and procedures were not followed," said David Sanders of the Department of Homeland Security, in a letter obtained and reported by the Associated Press. Other women have reported that they were molested while being patted down and searched by the same detention guard at the T. Don Hutto center. The Hutto allegations follow a number of other cases of sexual assault in detention centers. In May of this year, a detention guard was convicted to three years in jail for sexually assaulting women detained in the Port Isabel Detention Center in South Texas. The guard admitted to sneaking into the detention center's medical wing and sexually assaulting patients. In 2007, a Hutto guard was fired, though not prosecuted, after allegations of sexual abuse. The lack of prosecution drew charges that ICE engaged in a cover up. The Hutto Detention Center is run by the Corrections Corporation of America (CCA), a private prison company. An ICE spokesperson told the AP that CCA has been put on probation as a result of the allegations. But according to Bob Libal of the group Grassroots Leadership, which advocates for detention reform, it's unclear what "probation" means. "It seems absurd that an incident like this would not mean an end of the contract with CCA, especially since it's not the first time," said Libal.