Acting Homeland Security Secretary Kevin McAleenan on Wednesday announced an investigation into "disturbing & inexcusable" social media posts allegedly made by Border Patrol agents.
"These statements are completely unacceptable, especially if made by those sworn to uphold" the agency's standards, McAleenan said in a pair of tweets announcing the "immediate" probe.
"Any employee found to have compromised the public's trust in our law enforcement mission will be held accountable," McAleenan added.
McAleenan launched the probe on the heels of a damning expose by investigative news outlet ProPublica revealing graphic and callous posts about migrants and Democratic lawmakers that were allegedly made in a private Facebook group by current and former Border Patrol officers.
Members of the group reportedly cracked jokes about dead migrants and shared sexually explicit memes involving progressive Rep. Alexandria Ocasio-Cortez, D-N.Y., who has been a chief critic of the Trump administration's immigration policies.
Immigration has been among the most politically divisive and highly scrutinized issues during Donald Trump's presidency. Democrats have railed against former DHS Secretary Kirstjen Nielsen's handling of the influx of migrant families coming to the border, as well as Trump's long-held campaign promise to build a wall across the border and former Attorney General Jeff Sessions's "zero tolerance" policy that led to an influx of family separations.
That political tension ratcheted up following recent reports about the cramped and derelict conditions for children and adult migrants being held in U.S. facilities. Acting Customs and Border Protection Commissioner John Sanders will resign Friday amid the political turmoil, a CBP official announced last week.
Democratic lawmakers, including many of the two dozen presidential candidates, have flocked to tour the facilities in the wake of the reports.
Ocasio-Cortez visited facilities in Texas this week. She said that one migrant was told by Border Patrol officers to drink out of a toilet. "This is [Customs and Border Protection] on their best behavior, telling people to drink out of the toilet," Ocasio-Cortez told reporters. Immigration officials have denied that migrants were instructed to drink out of toilets.
On Thursday, the House passed the Republican-majority Senate's $4.6 billion emergency aid bill even as liberal Democrats had opposed the plan, saying it didn't go far enough to provide protections for the treatment of migrants at the holding facilities.