ANDREW LELLING, the US Attorney for Massachusetts, is emerging as a loyal Donald Trump lieutenant in one of the bluest states in the country.

Little was known about Lelling when Trump nominated him for the post last September. He had worked the previous 12 years in the office, first under Michael Sullivan and then Carmen Ortiz, an appointee of Barack Obama. He focused on international drug trafficking and white collar crime, including the prosecution of executives associated with a billion-dollar pyramid scheme and Carlos Rafael, the infamous Codfather of New Bedford. Prior to coming to Massachusetts, he worked as an assistant US attorney in Virginia and at the Department of Justice’s civil rights division.

Under Lelling, the US Attorney’s office appears to be functioning much as it always has, except the office seems preoccupied with immigration issues. There’s been a sharp uptick in press releases about prosecutions, and what’s distinctive about the press releases is how they highlight the nationality and immigration status of the defendants.

“One of the things we wanted to highlight, in keeping with the president’s priorities, was to at least bring into the public conversation that there is some fraction of the illegal immigrant population in this country that is committing a number of other offenses,” Lelling told CommonWealth’s Jack Sullivan. “My position on this is if you have someone who is in the United States illegally and commits an offense, we should be bringing to the public’s attention that correlation.”

The drumbeat on immigration ratcheted up a notch Thursday when Attorney General Jeff Sessions came to town and joined Lelling in announcing the prosecution of more than two dozen people for identity and benefit theft. As the first paragraph of the press release noted, nearly all of them were “unlawfully present in the United States.”

The defendants allegedly stole the identities of US citizens and used those identities to obtain state identification cards, federal benefits, and public housing subsidies. “These government programs are intended to help the poor, the elderly, American citizens, not those who are trespassing in the country,” Sessions said at a news conference at the federal courthouse in Boston, standing next to Lelling. “This kind of fraud is a theft from our seniors, a theft from our taxpayers, and a theft from the needy. A theft from America.”

Lelling praised Sessions as a leader who has “rededicated the Department of Justice to the rule of law,” while Sessions said he had given the go-ahead for Lelling to hire five more prosecutors.

“I’m excited to see this office thrive,” Sessions said. “The public servants in this office are doing great work.”

Boston Herald columnist Joe Battenfeld said the anti-immigration focus of Sessions and Lelling is no accident. He said Sessions keeps coming back to Boston and New England to talk about illegal immigration and sanctuary cities to put would-be presidential contenders such as Sen. Elizabeth Warren and Deval Patrick on the defensive.

At Thursday’s press conference, Sessions said Boston is one of the top areas in the country for illegal immigration, with an estimated 180,000 people living here without documentation.

“I can’t imagine why a city or a county or a state would think that someone who enters the country illegally who is subject to being deported for that alone is somehow to be protected even when they commit serious offenses,” he said.