Former President Donald Trump was named as an unindicted co-conspirator today in the investigation by the Michigan attorney general’s office into interference in the 2020 election.

Charges have already been brought in Michigan against 15 Republicans who acted as fake electors for Trump after President Joe Biden defeated him in the state in 2020.

During pretrial hearings in the case this week in Lansing, Michigan, a special agent for the attorney general’s office, Howard Shock, said the investigation was still open. He named a number of people he said had taken part in the conspiracy but have not been indicted, including Trump; Mark Meadows, the former White House chief of staff, and Rudy Giuliani, Trump’s former personal lawyer.

Defense lawyers for the Michigan fake electors, and some of the electors themselves, have been critical of the actions of the Republican Party and the 2020 Trump campaign, saying that lawyers and operatives had led the fake electors astray.

Whether Trump or any of his former aides or advisers face legal jeopardy in Michigan is unclear. Michigan is one of five swing states that are conducting investigations or prosecutions related to steps Trump and his allies took in trying to circumvent the will of voters after the 2020 election.

Georgia has brought charges against Trump, Meadows and Giuliani, among others. Nevada, like Michigan, has focused thus far on Republicans there who acted as fake electors, charging all of them. Charges are expected soon in Arizona, and Wisconsin is conducting an investigation.

Trump has also been charged in two federal cases brought by Jack Smith, the special counsel appointed by the Justice Department, including one that focuses on election interference in 2020.

Trump’s biggest legal challenge at the moment, though, is the criminal trial now in progress in New York City, where he faces charges related to hush money payments made to a porn actor, Stormy Daniels.

The election cases are playing out in five states that are likely to be crucial in deciding who wins the presidency in November. In Michigan, a lingering question has been whether others besides the fake electors could face charges.

During a hearing in the case Tuesday, George Donnini, a lawyer for one of the fake electors, Kathy Berden, focused on the role of Mike Roman, a former Trump campaign operative who has also been identified as an unindicted co-conspirator in the Michigan case.

Email and text traffic unearthed in various inquiries have shown that Roman played a key coordinating role in the Trump campaign’s plan to put forward slates of fake electors in swing states that Trump lost.

Roman, who has been charged in the Georgia case along with Trump and others, blocked efforts to add language to the documents signed by the fake electors in December 2020 that would have stated that they were only acting as a contingency, in case litigation challenging the election in that state succeeded. The phony Michigan certificate, which was sent to Congress, falsely stated that those who signed were the state’s “duly elected and qualified electors.”

“Isn’t he a bad guy here?” Donnini asked Shock in court Tuesday, referring to Roman.

“Yes,” Shock replied, adding that “the investigation is ongoing.”

“Well, maybe you should charge Mike Roman and not a retired farmer,” Donnini said, referring to Berden, a committee member for the Republican National Committee who comes from a farming family in Michigan.

Another defense lawyer, Duane Silverthorn, said today that his client, Michele Lundgren, had tried to cooperate with the office of Dana Nessel, the Michigan attorney general. Silverthorn went on to reveal that during an interview with the office, Lundgren had expressed “anger directed at the Republican Party,” a characterization that Shock agreed with.

Nessel’s office has already dropped charges against one of the Michigan fake electors, James Renner, as part of a cooperation agreement. Renner, a former state trooper, told the office last year that after reviewing testimony from the House investigation of the Jan. 6, 2021, attack on the Capitol, he had realized with dismay that he and the other electors had acted improperly.

“I can’t overemphasize how, once I read the information in the J6 transcripts, how upset I was that the legitimate process had not been followed,” Renner said in the interview, according to an audio recording obtained by The New York Times. “I felt that I had been walked into a situation that I shouldn’t have ever been involved in.”

Because of the number of defendants involved in the Michigan case, the presiding judge, Kristen D. Simmons, has divided the pretrial hearings in two. The hearings for the first group of defendants concluded today. Simmons said she would not decide whether the whole case would proceed to trial until after the hearings for the second group are concluded.

This article originally appeared in The New York Times.