U.S. Customs and Border Protection is projected to arrest roughly 37,000 people at the border in June, based on arrest data from June 1-16, a DHS official told POLITICO. | David J. Phillip/AP Photo Border arrests projected to drop in June

The pace of arrests on the U.S.-Mexico border dropped in June, according to a preliminary government estimate — potentially signaling that the Trump administration's controversial "zero tolerance" policy discouraged migrants from traveling north.

U.S. Customs and Border Protection is projected to arrest roughly 37,000 people at the border in June, based on arrest data from June 1-16, a DHS official told POLITICO.


If that trend held after June 16, it would represent roughly an 8 percent falloff from May — a decline that might demonstrate that zero-tolerance prosecutions of undocumented migrants who crossed the southern border, and the family separations that resulted, created a disincentive for Central Americans to attempt unauthorized entry to the U.S.

Vice President Mike Pence tweeted Tuesday, "To the people of Central America: You are our neighbors. We want you & your nations to prosper. Don’t risk your lives or the lives of your children by trying to come to the US on a road run by drug smugglers & human traffickers. If you can’t come legally, don’t come at all." He was repeating remarks he delivered Tuesday in Brasilia, the capital of Brazil.

It remains to be seen whether the decline continued after June 20, when President Donald Trump signed an executive order requiring that families be detained together. U.S. Customs and Border Protection Commissioner Kevin McAleenan told reporters Monday that Border Patrol agents were no longer referring migrant families to the Justice Department for prosecution, effectively suspending zero tolerance.

The projected June dip in border arrests may well have nothing to do with government policy. Randy Capps, director of research for U.S. programs at the nonpartisan Migration Policy Institute, said the pace of arrests matched seasonal trends. In recent years, border arrests have typically risen in March, plateaued in April and May, then dropped in June.

“Still too early to tell,” Capps said, “but no signs of a major shift in apprehensions patterns yet.” The projected June arrest figures match closely the June average over the last decade.

The Department of Homeland Security declined to comment.

The number of people caught at the southwest border plunged during President Donald Trump’s first year in office, but has climbed in his second year. The number nonetheless remains low compared to border arrests during the previous two decades.

Under the zero-tolerance strategy, launched fully in May, the administration sought to refer all people suspected of crossing the border, including families, for prosecution under federal illegal entry and reentry statutes.

The policy led to a sudden rise in family separations along the border, with more than 2,300 children split apart from adults during a nearly five-week period in May and June. A national furor over the family separations prompted Trump to end family separations, in effect also ending zero tolerance, because there was insufficient detention space to house families. The White House, however, continued to insist that the policy hadn’t changed.

A DHS official cautioned against drawing conclusions about border enforcement based on a two-week sample of arrest data. Central American migrants may have been en route to the U.S. before the administration’s hard-line border policy became widely publicized, the official said. “I would be hesitant to read a lot into it."