Acting Commissioner of Customs and Border Protection Mark Morgan will brief media in the James S. Brady Press Briefing Room at 11am
CNN  — 

Customs and Border Protection apprehended more than 42,000 migrants at the southern border in October, continuing a downward trend in arrests after record highs earlier this year, acting CBP Commissioner Mark Morgan announced Thursday.

The decline in arrests is in line with a recent downward trend following a peak in May, when apprehensions spiked to nearly 133,000. The administration has credited a series of policies – including the program informally known as “remain in Mexico” and regional partnerships – for the drop in arrests.

“This administration has and continues to take bold action to address this crisis and the numbers show it’s working,” Morgan said at a news conference in the White House briefing room, noting that there was a 14% decline in arrests in October compared to September.

Border Patrol arrested 35,444 migrants on the southern border in October, compared to 40,507 in September, according to agency data, and 9,806 people were deemed inadmissible.

The number of migrants arriving at the US-Mexico border skyrocketed last year as CBP apprehended and deemed inadmissible nearly one million people during the government’s 2019 fiscal year, Morgan announced last month.

Over the summer, border apprehensions reached record highs, straining the Department of Homeland Security’s resources and leading to overcrowding in border facilities. Earlier this year, CBP was holding roughly 20,000 people in custody. Now, the average is less than 3,500 detainees daily, according to Morgan.

The demographics of people arriving at the southern border earlier this year created an added challenge for the department. The majority of arrivals were from the Northern Triangle countries of Guatemala, El Salvador and Honduras, and many of them were families or unaccompanied children seeking asylum in the United States.

To staunch the flow of migrants, the administration introduced policies that dramatically limit who’s eligible for asylum in the United States, including a rule that prohibits migrants who have resided in or traveled through third countries from seeking asylum in the US.

The Supreme Court cleared the way for the rule, which bars people traveling through Mexico from being able to claim asylum, to go into effect nationwide while the appeals process plays out.

Morgan noted Thursday, however, that there was a shift in demographics in October, from majority Central American migrants to Mexican migrants.

“For the first time in nearly 18 months, Mexico was the country of origin for the majority of apprehensions and inadmissible aliens, rather than Northern Triangle countries, with single adults surpassing families,” he said.

Many of the policies rolled out by the administration so far do not apply to Mexican migrants.

CNN’s Maegan Vazquez contributed to this report.