In June, as reports surfaced of migrant children being separated from their families by Customs and Border Protection, Secretary of Homeland Security Kirstjen Nielsen spoke at a press conference to declare that the Trump administration "did not create a policy of separating families at the border." She also tweeted: "We do not have a policy of separating families at the border. Period."

On Tuesday, however, a redacted memo released by the government revealed that Nielsen signed off on a policy in April that stated that the Department of Homeland Security could "permissibly direct the separation of parents or legal guardians and minors held in immigration detention so that the parent or legal guardian can be prosecuted."

The memo, released as part of a Freedom of Information Act request by two government watchdog organizations (Open the Government and the Project on Government Oversight), reveals how the Trump administration was able to separate thousands of children from their parents while simultaneously denying the existence of a family separation policy.

While the memo does not explicitly require the separation of children from their parents and families, it outlines the administration's "zero-tolerance" policy, which ensured that every adult apprehended crossing the border would be detained and prosecuted. While this was not, on its surface, a family separation policy, it served as a mechanism to force the government to detain children separately from their parents. Because federal guidelines limit how restrictively and how long children can be detained, the DHS could argue that parents needed to be separated from their children so that the parents could be indefinitely detained and prosecuted.

Nielsen immediately came under fire in June for denying that the administration had a policy of separating children from their parents, even as outlets like the New York Times reported that over 700 children had been forced apart from their parents since October of 2017. On May 11th, in the midst of intense public backlash, Trump's incoming chief of staff John Kelly had defended family separation as a necessary evil that acted as a "deterrent" for illegal immigration. Five days later, Nielsen also defended the policy in a Senate hearing, though she continued to deny that Trump had ordered the separations. She held that "zero-tolerance" prosecution made every adult migrant a criminal, and therefore justified separating their children from them.

In June, a little over a week after Nielsen declared, "We will not apologize for doing our job" and separating families, a federal judge in California ordered the government to reunite separated children with their families.