WASHINGTON -- WASHINGTON (AP) - President Donald Trump's leading border official announced Sunday that an internal examination is underway into the background screening of an immigration enforcement agent who fatally shot a Colombian national in Maine, following disclosures from relatives to The Associated Press about the officer's prior mental health challenges and aggressive conduct.

Tom Homan stated that if reports about the Immigration and Customs Enforcement officer hold true, the individual should never have passed the vetting process.

"Multiple aspects are being examined," Homan noted during a CNN interview concerning Army veteran David Brouillette. "Training protocols are part of the review, and internal affairs is specifically assessing the vetting in this instance."

Concerns over the Department of Homeland Security's accelerated efforts to recruit, prepare and position thousands of new ICE agents for Trump's immigration enforcement push have intensified following consecutive fatal shootings involving immigrants in Maine and Houston.

Homeland Security Secretary Markwayne Mullin directed a temporary halt to vehicle stops after the Maine incident, yet Trump quickly overturned the decision and directed that such stops continue as essential to detaining and removing immigrants lacking valid legal status.

Homeland Security offered no immediate comment Sunday on the internal review.

Homan added that adjustments have occurred and acting ICE director David Venturella has implemented a fresh order requiring body-worn cameras during any vehicle stops by officers.

"At present, every vehicle stop includes at least one body camera to capture the full sequence," he said.

He noted that Venturella issued guidance mandating at least one body camera on vehicle stops to ensure complete video documentation.

It remains uncertain whether these departmental measures will address worries from some members of Congress regarding Homeland Security's preparation and methods in pursuit of Trump's large-scale deportation objectives.

Legislators across party lines have expressed concerns.

Democrats questioned ICE representatives in a private House Homeland Security Committee session last week, with several leaving with additional uncertainties.

Officials informed lawmakers in the session that 56 complaints of excessive force involving ICE agents have been filed, with 32 cleared and one sent for disciplinary review.

No penalties have been issued so far, according to the lawmakers, while the remaining cases continue under investigation.

Republican Sen. Susan Collins of Maine, who leads the Senate Appropriations Committee, has advocated for body-worn cameras and secured funding for their deployment. She described it as highly regrettable that the officer in the Maine shooting lacked a camera.

The Trump administration has not achieved its target of removing 1 million individuals annually, even amid vigorous immigration enforcement that has produced tense confrontations in cities across the country.

At least 10 deaths have occurred in interactions with immigration agents since the launch of Trump's deportation initiative.

Although the administration maintains it focuses on the most serious criminal offenders, outcomes have varied and U.S. citizens have also been among those killed.

The ICE agent fatally shot 25-year-old Johan Sebastian Duran Guerrero, a Colombian national, inside his vehicle near his residence in the coastal town of Biddeford.

In Houston, Lorenzo Salgado Araujo died on July 7 after ICE agents pursued his white work van through city streets and fired through the window in view of his work team, including his brother.

Earlier this year, two Americans demonstrating against ICE operations in Minneapolis, Renee Good and Alex Pretti, a 37-year-old nurse, lost their lives, prompting widespread criticism.

Democrats initiated the longest agency shutdown in history earlier this year by withholding funding for Homeland Security in an unsuccessful bid to impose restrictions on the agents.