Proof Trump's 'zero tolerance' immigration policy works? Border Patrol arrests drop sharply in June

For all of the outrage surrounding President Donald Trump's "zero tolerance" illegal immigration policy, which mandates the criminal prosecution of each immigrant who enters the United States illegally, new data from Customs and Border Protection suggests the policy could be effective.

Or maybe it's just the scorching desert heat.

What are the details?

According to The Associated Press, Border Patrol arrests "fell sharply" in June to a level not seen since February after four consecutive months of increases.

The data, which had not yet been publicly released and was provided to the AP by a CBP source, shows Border Patrol agents made 34,057 arrests on the U.S.-Mexico border in June, a 16-percent decrease from May when agents made 40,344 arrests.

It's not immediately clear what led to the drop-off. Two reasons exist: Either Trump's "zero tolerance" policy is working and acting as a deterrent for illegal immigration or the drop-off is attributed to seasonal trends and economic and logistical factors affecting migrants.

Data from previous years may provide additional clues. In 2017, May to June saw an increase in border apprehensions, according to CPB data, but the numbers — 19,940 to 21,657 — were down sharply from 2016 and this year. However, the data shows border arrests and apprehensions were down significantly after Trump was inaugurated and remained at low levels until the beginning of fiscal year 2018.

In 2016, the last comparable year of the Obama administration, May saw 55,442 apprehensions while June saw 45,777 apprehensions. The trend of less apprehensions in June compared to May goes back to at least fiscal year 2013. Last year was the only exception.

In addition, May has historically been a big spike month for southern border apprehensions, with the exception of this year and fiscal year 2013.

What did the CBP say?

The CBP declined to comment on the data because it was not yet checked for accuracy and released to the public. Still, CBP Commissioner Kevin McAleenan told reporters last month he believed the decrease in arrests was related to Trump's policy.

"I believe the focus on border enforcement has had an impact on the crossings," he said.

Is the policy still in place?

Yes, but it has been modified from the enforcement that began in May when the Trump administration announced the "zero tolerance" approach.

After weeks of outcry over parents being separated from their children at the border — a seemingly unintended consequence of the strict policy — Trump signed an executive order on June 20 "to keep families together."

Almost immediately following Trump's executive order, McAleenan ordered his agents to cease referring immigrants who illegally cross into the U.S. with children to the Department of Justice for criminal prosecution.