US Homeland Security Secretary Markwayne Mullin defended the Trump administration's border security and immigration enforcement policies on Thursday during a hearing that featured heated exchanges with Democratic lawmakers over deaths in immigration detention, family separations, and border wall construction.
Testifying on Department of Homeland Security oversight and operations before the House Appropriations subcommittee, Mullin argued that Mexican drug cartels continue to adapt their smuggling methods and remain a threat along the US-Mexico border.
"There's not one inch of Mexico's northern border that isn't covered by a plaza... They have plaza centers; they call them 'plazas,' and they have plaza bosses, and they're always looking for vulnerabilities to push human trafficking and drug trafficking across our border," he said.
Mullin said DHS is expanding physical barriers and surveillance systems to counter cartel activities, including the construction of primary and secondary border walls and the deployment of "smart fences" that alert authorities when barriers are breached.
"We're putting in smart fences, which allow us to respond when they're tampering with the wall. The second wall, which is a primary wall, will still be within our footprint; we're constructing it," he said, adding that unmanned aerial systems equipped with heat sensors are being used to detect and track illegal crossings in remote areas.
The hearing grew tense when Rep. Lauren Underwood questioned Mullin about deaths in immigration detention facilities. Underwood cited reports of medical neglect, abuse, and overcrowding within the immigration detention system and asked whether DHS had specific policies aimed at reducing deaths in custody.
Mullin disputed her characterization of the situation, telling the congresswoman that her figures are incorrect and calling her allegations "dangerous accusations."
"You were invited to this committee. This is my time. You are a guest," Underwood responded after the exchange became heated.
When pressed again on whether DHS has formal goals to reduce deaths in custody, Mullin replied: "We're doing a wonderful job at it. We have 0.009% of deaths."
The exchange came amid growing scrutiny of detention conditions. A report released Thursday by Human Rights Watch and Physicians for Human Rights said at least 52 people have died in ICE custody since the start of President Donald Trump's current administration and that the death rate in detention has increased.
Representative Mark Amodei, who chaired the hearing, intervened during several contentious moments, warning lawmakers and witnesses to maintain order.
"This is not 'Meet the Press' or Fox News or whatever for anybody involved," Amodei said. "It's what the question is, what's the answer."
Later in the hearing, Mullin highlighted DHS's role in securing the ongoing 2026 FIFA World Cup, saying the department had managed a major security operation across multiple host cities without significant incidents.
"We have 78 Super Bowls in 11 cities in 38 days," Mullin said, crediting cooperation among DHS agencies, including Customs and Border Protection, Immigration and Customs Enforcement, the Transportation Security Administration, and the FBI.
"We've had no serious major incident," he said, while acknowledging that authorities had responded to some threats.
‘Secretary, you should be ashamed of yourself’
The hearing became heated again when Rep. Rosa DeLauro questioned Mullin about family separations and reports that thousands of migrant children had been separated from relatives.
After a tense exchange, DeLauro asked whether the administration supported eliminating the Federal Emergency Management Agency (FEMA).
Mullin responded that "some portions" of FEMA could be eliminated but declined to give a direct yes-or-no answer.
In her closing remarks, DeLauro returned to the issue of deaths in immigration detention, arguing that the department needed a clear plan to address the problem.
"What we need... a policy, a plan in a timely fashion that says, how are we going to deal with these issues?" she said.
After lawmakers concluded the hearing, an individual shouted accusations at Mullin as he was leaving the room.
The protester accused the secretary of enabling family separations, terrorizing immigrant communities, and failing to protect the rights of migrants in US custody.
The individual also criticized Mullin's support for President Donald Trump's immigration agenda and alleged abuses within the immigration enforcement system.
"Secretary, you should be ashamed of yourself. How dare you? You are the American Gestapo ... You are disgusting. You could be ashamed of yourself," he shouted.