June 18th 2018, Department of Homeland Security Kirstjen Nielsen to the press:

“this administration did not create a policy of separating families at the border”
“We will separate those who claim to be a parent and child if we cannot determine a familiar or custodial relationship exists.”
“We also separate a parent and child if the adult is suspected of human trafficking. […] adults and children arriving at the border […], claiming to be a family unit.”
“And separation can occur when the parent is charged with human smuggling. Under those circumstances, we would detain the parent in an appropriate secure detention facility separate from the child.”
“Everyone is subject to prosecution.”
“When D.H.S. refers a case against a parent or legal guardian for criminal prosecution, the parent or legal guardian will be placed into the U.S. Marshals Service […] and any accompanied child will be transferred to the Department of Health and Human Services and will be reclassified as an unaccompanied alien child.
“parents who entered illegally are, by definition, criminals.”

(New York Times https://www.nytimes.com/2018/06/18/us/politics/dhs-kirstjen-nielsen-families-separated-border-transcript.html)

By criminalizing everyone who crosses the border with a child in their arms, even those who are seeking amnesty, the Trump Administration has effectively weaponized the TVPA – an anti-human-trafficking act, designed to keep people safe – and reclassified everyone as a suspected human trafficker or criminal. Nullifying the act of seeking amnesty. See: genocide, definition. (https://www.bbc.com/news/world-11108059)