The chief of the Border Patrol’s El Paso sector says President Trump should get the credit for a break in a historical trend in illegal immigration.

New data out for the month of May shows the Border Patrol apprehended 19,967 illegal immigrants last month. That’s 35,475 fewer apprehensions than the 55,442 in May 2016.

“The administration has communicated clearly that they support our people out in the field that they will enforce our immigration laws and there will be consequences to those who violate those laws,” Jeffrey Self, Chief Patrol Agent for the El Paso Sector, told Fox News during a recent ride along.

Self also credits the ending of the “catch and release” program as well as new infrastructure for the downward trend in border arrests.

Catch and release is the unofficial name for a longstanding protocol where illegal immigrants are arrested for being in the U.S. but are released as they wait for a hearing.

Historically, the number of illegal immigrants arrested across the southern border and the number of immigrants attempting to cross spikes from February to June. Not this year. The downward trend in apprehensions that started when President Trump took office has continued through Spring.

“As a result of the border security initiatives that we’ve implemented, it has sent a clear message that there will be a consequence applied to any illicit traffic,” said Self.

April 2017 had the smallest number of Border Patrol apprehensions in five years, at 15,780. This year is the first time in at least five years that apprehensions have dropped below 20 thousand a month.

Self said the Trump Administration has created what he calls a mindset of deterrence.

The Border Patrol conducts post arrest interviews with illegal immigrants. Self said the arrestees from Central America say there is a perception that the dangerous journey to America may not be worth the risk because the chances of being sent back are much higher. Self said it’s a definite indicator the Border Patrol is having an effect.

“It makes them think twice about taking their life savings, giving it to a smugglers, getting on this track and coming to the United States. Just to get here and returned to your country of origin,” Self said.

He added that there’s been a stronger effort to capture and prosecute human smugglers and drug traffickers. He also said additional funding, new technology and infrastructure also helps. The infrastructure includes new fencing in the El Paso sector – which started before Trump won the 2016 election.

Self said there has also been an initiative to conduct more joint operations with other local, state and federal law enforcement agencies, in addition to their counterparts in Mexico.

Although numbers have trended down for the first few months of the year, when they typically trend up, Self still anticipates a rise in immigration this summer. Signs of that began in May when the Border Patrol arrested about 4,000 more illegal immigrants than they did in April.