There were no SWAT teams, no guns drawn. The operation was "respectful" and "courteous," he told ABC News today.
ABC News has learned that the raids began at 7:30 a.m. Monday. Cohen was inside the New York City hotel room where he's been staying when FBI agents suddenly showed up at his door.
But it was clear the FBI agents were there for a reason, seizing electronic devices, phones and financial documents dating back to 2013.
This was a very rare move -- to raid someone's personal lawyer, in this case, Trump's.
A source who saw the search warrant told ABC News today that Cohen is being investigated for possible bank and wire fraud after that $130,000 payment to porn star Stormy Daniels, which paid for her silence just 11 days before the election.
Daniels claims she had an affair with the president in 2006, which the White House has denied.
Just five days ago, Trump broke his public silence on Daniels, saying he did not know anything about Cohen's payment to her.
Trump claimed on Thursday not to know where the money Cohen used came from, ignored a question about whether he ever set up a fund that Cohen could draw from and directed further inquiries to the attorney himself.
"You'll have to ask Michael Cohen," he said. "Michael is my attorney. You'll have to ask Michael."
Cohen has said he came up with the money, using a home equity line of credit, and claims did not inform his own client, the future president.
Investigators are tracing his steps, including how the money was transferred to a shell company and then to an attorney in Beverly Hills, California.
Critics argue that Cohen might have also broken campaign finance law and that the $130,000 was, in essence, a campaign contribution that was aimed at helping Trump win and that was never disclosed.
And today, The New York Times is also reporting the FBI was hunting for documents related to the payment to former Playboy model Karen McDougal who claims she also had an affair with Trump.
She also claims that she was paid by the National Enquirer for her story and that the story was never printed.
"There were real feelings between the two of us, not just myself, not just him," she has said. "There was a real relationship there."
But because it was not about Russia, Mueller alerted Deputy Attorney General Rod Rosenstein.
Rosenstein then alerted the U.S. Attorney's Office in the Southern District of New York, which looked at the same material and decided they needed to act and quickly.
However, the White House when pressed today would not say whether Cohen still works for Trump.
"I'm not sure. I'd refer you to Michael Cohen on that," White House press secretary Sarah Sanders said.