In prepared testimony released on the eve of his appearance Thursday before the Senate Intelligence Committee, former FBI director James Comey placed President Donald Trump in the sights of a federal criminal investigation, laying out evidence sufficient for a case of obstruction of justice.

Comey proved the president had specifically attempted to shut off at least a major piece of what Trump calls the "Russia thing," the investigation into the misleading statements by fired national security adviser Michael Flynn concerning his role in dealings with the Russians. This kind of presidential intervention in a pending criminal investigation has not been seen, to my knowledge, since the days of Richard Nixon and Watergate.

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Comey's statement meticulously detailed a series of interventions by Trump soliciting his assistance in getting the criminal probe dropped. These details are red meat for a prosecutor. Presumably, the team of experienced criminal prosecutors that special counsel Robert Mueller has assembled will be following up on this crucial testimony, which rests on contemporaneous memorandums that Comey was sufficiently alarmed to prepare immediately after receiving the president's requests.

The obstruction of justice statute prohibits not only successful interference with pending criminal investigations but also any use of "threats" to "endeavor" to obstruct an investigation.

Moreover, Comey's testimony also supplies the element of "threats." He vividly describes a dinner with the president on Jan. 27, which the president surprisingly limited to just the two of them. The president asked Comey whether he liked his job and wanted to continue in it, even though, before the inauguration, the president had asked Comey to stay on the job, and Comey had eagerly accepted.

Leaving little doubt about the price of continued retention, the president twice, according to Comey, told him that he expected "loyalty" from Comey, just as he did from everyone else around him.

Then, on Feb. 14, the president carefully structured another one-on-one meeting with Comey, specifically ordering Attorney General Jeff Sessions, to whom the FBI director ordinarily reports, to leave the Oval Office where Comey, Sessions and other national security officials (and Jared Kushner) had been meeting. At that point, the president laid his cards on the table, according to Comey: "I hope you can see your way clear to letting this go, to letting Flynn go. He is a good guy. I hope you can let this go."

Next, in phone calls on March 30 and April 11, the president solicited Comey's help in removing the "cloud" over Trump resulting from the FBI investigation into Russian interference in the 2016 election and possible Trump campaign collusion. The president again demanded loyalty: "Because I have been very loyal to you, very loyal; we had that thing you know." He pressed Comey to make public statements exonerating the president, but Comey declined to do so.

The president dropped the other shoe on May 9, summarily firing Comey. The White House initially blamed this on Comey's actions during the 2016 campaign, but within the week Trump admitted that the cover story was a sham. He brazenly stated that he fired Comey in order to bring the "Russia thing" to a close, and he bragged to senior Russian officials in a private Oval Office meeting that this is what he thought that he had accomplished by sacking Comey.

Comey's statement lays out a case against the president that consists of a tidy pattern, beginning with the demand for loyalty, the threat to terminate Comey's job, the repeated requests to turn off the investigation into Flynn and the final infliction of career punishment for failing to succumb to the president's requests, all followed by the president's own concession about his motive. Any experienced prosecutor would see these facts as establishing a prima facie case of obstruction of justice.

But whether a sitting president may be indicted while in office is an open question. I advised the Watergate special prosecutors (and argued to the Supreme Court in the Nixon tapes case) that the president enjoys no unique immunity from obeying criminal laws. Other Justice Department officials, however, have taken a contrary position.

The ball now is in Mueller's court to decide whether he has (or will have) enough evidence to charge Trump with obstruction and, if so, whether the president, like everyone else in our system, is accountable for committing a federal crime.

Philip Allen Lacovara is a former U.S. deputy solicitor general in the Justice Department and served as counsel to Watergate special prosecutors Archibald Cox and Leon Jaworski. He wrote this column for The Washington Post. Email: placovara@mayerbrown.com

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