In recent weeks, some have suggested that President Trump’s controversial interactions with James Comey, the former F.B.I. director, did not constitute wrongdoing. As an ex-criminal defense lawyer and a former federal corruption prosecutor, now joined together as government watchdogs, we beg to differ. Mr. Comey’s sworn statement and answers before the Senate Select Intelligence Committee now provide strong evidence that President Trump committed obstruction of justice. But we have miles to go before that case is legally resolved one way or the other — if it ever is.

The crime of obstruction requires an attempt to block an investigation with corrupt intent. Mr. Comey has now given us direct witness testimony of obstruction by the president in the form of the already famous statement “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.” Mr. Comey repeatedly added in today’s questioning that “I took it as a direction” that “this is what he wants me to do.” In a system governed by the rule of law, shutting down an investigation to benefit a friend — or perhaps, to keep damaging information that friend may know from emerging — is corrupt.

Importantly, Mr. Comey also confirmed the existence of an open investigation at the time of Mr. Trump’s statement — a legal predicate for an obstruction offense. And he added detail to the obstruction pattern that began with President Trump’s demand for “loyalty” and culminated in Mr. Comey’s firing and events immediately thereafter. After the past 24 hours, there can no longer be any doubt that President Trump should be investigated for obstruction. Indeed, Mr. Comey suggested that such an investigation may already have begun: “That’s a conclusion I’m sure the special counsel will work toward, to try and understand what the intention was there and whether that’s an offense.”

Mr. Comey’s testimony also further undercuts the claim by some commentators that the law was not violated because there was no “proceeding” for President Trump to obstruct. F.B.I. investigations are proceedings, and a number of courts have found them to be so in the obstruction context, though the matter is not fully settled. The bureau is also working in connection with a grand jury investigation, as is common in major criminal matters, and the law is crystal clear that obstruction of a grand jury is a crime, as is obstruction of congressional proceedings like the one here. It also doesn’t make sense to suggest that Mr. Trump’s unquestioned legal right to fire Mr. Comey allows him to do so corruptly. Mr. Trump could not, for example, take a bribe from Vladimir Putin to fire Mr. Comey; neither can he do so to benefit a friend or protect himself.