Details of President Donald J. Trump’s revised plans to deport people living in the United States without proper documentation came into sharper focus on Feb. 21. A pair of memos from the Department of Homeland Security propose hiring up to 15,000 additional federal agents to focus on immigration violations and broadly expand guidelines on the kinds of offenses that can trigger deportation. A senior attorney with the Catholic Legal Immigration Network said that the anxiety these moves will likely provoke among immigrant communities makes the situation “a recipe for disaster.”

The memos state that immigration officials “no longer will exempt classes or categories of removable aliens from potential enforcement” and that officers “have full authority to arrest or apprehend an alien whom an immigration officer has probable cause to believe is in violation of the immigration laws.”

According to a question-and-answer document on the Department of Homeland Security’s website, even nonviolent crimes, such as driving without a license, could lead to deportation.

During the Obama administration, undocumented people in the United States faced immediate deportation if they were convicted of certain crimes or if they had entered the United States less than 14 days before capture and were apprehended within 100 miles of the U.S. border.

A senior attorney with the Catholic Legal Immigration Network described the new rules as “unnecessarily draconian” and predicted that they would split up families.

But under the rules outlined by Homeland Security Secretary John Kelly, almost any person living illegally in United States could face deportation. Undocumented individuals who have been charged or convicted of any crime — and even those suspected of a crime — will now be an enforcement priority. That could include people arrested for shoplifting or minor traffic offenses or those deemed a threat to a community by local law enforcement.

Additionally, rather than focus on a certain area of the border for people crossing illegally, officials would be empowered to make arrests throughout the nation. The memos also expand the timeframe of a “recent” arrival from two weeks to two years and specify that undocumented people may be deported to Mexico rather than held and then repatriated to their countries of origin. The latter is the current practice, a process slow enough to allow many held for deportation to appeal their determinations.

Michelle Mendez, a senior attorney with the Catholic Legal Immigration Network, or CLINIC, described the rules laid out in the memos as “unnecessarily draconian” and predicted that they would split up families. She pointed to new rules about partnerships with local police and changes to how the federal government classifies unaccompanied minors as particularly troubling.

“We have so many advocates who are receiving text messages and phone calls [from clients] asking if they should go to the grocery store, go to church or send their kids to school because they’re afraid they’ll be picked up,” Ms. Mendez said.

Those fears are now warranted, Ms. Mendez said. She worries that the anxiety generated by Mr. Trump’s recent executive orders, together with the new Homeland Security memos, will mean that undocumented people will fall victim to scam artists promising assistance on immigration penalties.

“There is mass hysteria and people who try to profit from that hysteria,” she said. “It’s a recipe for disaster.”

The memos also address Mr. Trump’s promise to build a wall along the U.S.-Mexico border, one of the president’s signature campaign commitments, though they suggest that in some areas, a fence or even sensors may be used instead of a wall.

The Department of Homeland Security has said it has identified locations to build a wall, including El Paso, Texas, and near Tucson, Az., where existing border fences have been deemed no longer effective. It is also assessing other areas where there is currently no fencing in order to “build a wall or similar physical barrier on the border where it currently does not exist.”

The new policies still abide by Obama-era exemptions for the roughly 750,000 undocumented people living in the United States brought here as children, known as Dreamers, and Homeland Security officials have said that even with the new rules, large-scale immigration raids are not expected.

Michael J. O’Loughlin is national correspondent at America and author of Hidden Mercy: AIDS, Catholics, and the Untold Stories of Compassion in the Face of Fear.