Steven Cash, who worked in the Manhattan DA’s office from 1987 to 1994, shared his assessment Wednesday, a day after attorney Carey Dunne from Manhattan District Attorney Cy Vance’s office wrote that “the criminal investigation is proceeding based upon information derived from public sources, confidential informants, and the grand jury process.” Cash now serves as counsel for Day Pitney LLP.

“Do not underestimate the degree to which the Manhattan DA is independent, and how little it cares, institutionally, about the politics,” Cash tweeted. “If this report is true, POTUS and family should be very, very, concerned.”

Cash, who said he knows Vance, explained to Newsweek that “anybody who’s on the receiving end of the Manhattan DA’s office should be very concerned.”

“They don’t do this for political reasons, they wouldn’t do this for the press. They take really seriously their role,” Cash said. “And they certainly wouldn’t be dealing with a grand jury or subpoenas unless they had made initial determinations that this is real.”

Cash added that “the grand jury could indict them,” referring to Trump and his family.

Manhattan’s DA is probing how Trump’s family business, the Trump Organization, recorded payments to adult film star Stormy Daniels to silence her about her alleged affair with Trump, leading up to the 2016 presidential election. The office has subpoenaed eight years’ worth of Trump’s tax returns from his accounting firm Mazars USA.

If indicted, Trump and his family will be “all on nearly equal ground,” Cash said, but pointed out that no court has resolved the issue of whether a state can indict a sitting president.

“I don’t think there’s any legal issue about whether a state can indict a family member of a sitting president or his associates,” Cash added.

Because the Manhattan DA’s office is not under the control of the executive branch of the federal government, it is unlikely that Trump could use pardon powers on his family members, Cash said.

“Attorney General [William] Barr may care what the president thinks but Cy Vance doesn’t care. All he cares about is the people of the state of New York,” Cash said, adding that the motto of the Manhattan DA’s office is “with neither fear nor favor, we will follow the evidence wherever it takes us.”

The Manhattan DA’s office declined to comment to Newsweek on Wednesday. The Trump Organization and White House did not immediately respond to requests for comment.

A Manhattan federal judge last week said that Trump’s tax returns are fair game for the investigation. Trump appealed the decision and said a “parade of horribles” would follow if the subpoena is enforced, a remark Dunne dismissed.