Rep. Bennie Thompson, a Mississippi Democrat, sent a letter Friday to the Homeland Security Department's acting inspector general requesting an investigation into whether Customs and Border Protection and Department of Homeland Security leadership -- specifically acting Homeland Security Secretary Kevin McAleenan, acting Customs and Border Protection Commissioner Mark Morgan and Border Patrol Chief Carla Provost -- knew about or addressed allegations that Customs and Border Protection agents had "posted violent, racist, misogynistic comments and pictures" in the groups.

"Such vile and threatening behavior from agents of the United States Government is entirely unacceptable, should be grounds for immediate dismissal from service, and is the subject of an investigation by CBP's Office of Professional Responsibility," Thompson said.

Thompson's request comes on the heels of Customs and Border Protection officials announcing an investigation into "disturbing social media activity" after a published report of a closed Facebook group for current and former Border Patrol agents called "I'm 10-15." The group reportedly featured jokes about migrant deaths and derogatory comments about Latina lawmakers.

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