WASHINGTON (AP) — The Justice Department has escalated its investigation over an Alaska Senate candidate who shares a name with the Republican incumbent, issuing a letter to a prominent Democratic attorney in Washington and others that they may be targets of the criminal inquiry, two people familiar with the matter said Tuesday.

The target letter to attorney Marc Elias, who for years has represented Democratic campaigns as well as the party itself in election-related challenges, is one of multiple such letters that were issued, said the people, who spoke on condition of anonymity to discuss an ongoing investigation. They mark an overt widening of the investigation into potential voter confusion in the state.

“No one should be surprised that President Trump’s Department of Justice is targeting me and my law firm on Election Day. This administration has repeatedly weaponized the DOJ against the President’s political enemies despite zero evidence of wrongdoing, and we are the latest targets,” Elias said in a statement Tuesday.

A target letter is a letter that the Justice Department sometimes sends to individuals whom it sees as at legitimate risk of indictment. The department defines a “target” as a person against whom it has gathered substantial evidence linking them to a possible crime and regards as a potential defendant.

News of the target letters surfaced on Election Day in a race headlined by two-term Republican Sen. Dan Sullivan and Democratic former U.S. Rep. Mary Peltola. The race is among a handful nationwide expected to determine control of the Senate.

Alaska U.S. Attorney Michael Heyman told reporters in Anchorage that the investigation has been ongoing for several months. But recent revelations from The New York Times that Peltola’s campaign appeared to be involved in recruiting retired teacher Dan J. Sullivan have resulted in a “significant surge of law enforcement assets to Alaska.”

More than 100 subpoenas have been issued as part of the investigation, one of the people briefed on the probe said.

The Justice Department does not typically require targets of its investigations to testify before a grand jury in part because of constitutional protections against self-incrimination.

In this case and others, though, getting a target letter does not necessarily mean that a person will be indicted. The Trump administration has repeatedly struggled to secure grand jury indictments in politically sensitive cases.

“We will not be intimidated by a sham investigation. We are going to keep working around the clock to support our clients and make sure President Trump and his party enjoy a well-deserved beating at the ballot box,” Elias said in a statement.

He did not return messages seeking comment.