Paul Callan is a CNN legal analyst, a former New York homicide prosecutor and current counsel at the New York law firm of Edelman & Edelman PC , focusing on wrongful conviction and civil rights cases. Follow him on Twitter @paulcallan . The opinions expressed in this commentary are his own.

(CNN) Early Sunday afternoon President Donald Trump elevated Twitter to a virtual Cabinet position in his administration. He used it, rather than the attorney general, to order a possible criminal investigation of a counterintelligence operation conducted by the Department of Justice and the FBI.

The President tweeted:

"I hereby demand, and will do so officially tomorrow, that the Department of Justice look into whether or not the FBI/DOJ infiltrated or surveilled the Trump Campaign for Political Purposes - and if any such demands or requests were made by people within the Obama Administration."

I hereby demand, and will do so officially tomorrow, that the Department of Justice look into whether or not the FBI/DOJ infiltrated or surveilled the Trump Campaign for Political Purposes - and if any such demands or requests were made by people within the Obama Administration!

This may be the first Department of Justice criminal investigation ordered via Twitter feed. Given the importance of a presidential decision regarding a possible criminal investigation, the use of Twitter was completely inappropriate. It trivializes the entire process. What's next in the presidential communication arsenal, the use of Facebook and Instagram with photos?

One would have expected a conference with the deputy attorney general so that the implications of such an important decision could be weighed and evaluated. Ordering such an investigation via Twitter is a disgraceful exercise of prosecutorial power by the President of the United States. We can only hope that Trump doesn't lead the nation into war via Twitter before consulting with the proper military advisers.

The US Constitution designates the president as the nation's chief executive -- in charge of all agencies in the executive branch of the federal government. Since the Department of Justice and the FBI are part of the executive branch, the president has final authority over the operation of those agencies. As such, in the absence of a provable "corrupt intent" to obstruct justice or engage in unlawful activity, his order to initiate an investigation of the FBI and Justice Department as outlined in his tweet would be presumptively legal.

In modern times, though, most presidents have taken a hands-off approach with respect to specific criminal investigations in a deliberate effort to keep them out of partisan politics and to preserve public respect for the integrity of federal law enforcement authorities.

That sensible precedent has been shattered by Trump's unapologetic criticism and suggestions regarding ongoing investigations and the investigators themselves. He has repeatedly attacked his own Attorney General, Jeff Sessions, calling him weak and disloyal, among other things.

He has directed similar diatribes at high ranking members of the FBI as well as FBI investigative teams probing Russian interference in the American presidential election.

While the President constantly urges a quick conclusion to the Mueller investigation with the mantra of "no evidence of collusion," and "witch hunt," his Twitter directive Sunday may actually extend and complicate the probe.

Surprisingly Deputy Attorney General Rod Rosenstein, the man in charge of Mueller and the Russia investigation since Sessions' recusal, immediately complied with the President's tweetstorm. Rather than waiting for the President to make his "demand" official, as promised in the Twitter feed, Rosenstein pulled the trigger immediately, ordering the inspector general to investigate the matter.

Ironically, the call for a new investigation occurred on the same day that presidential "pro bono" counsel Rudolph Giuliani told the New York Times that the Mueller team had hinted that the "Russia Investigation" might end as early as September if the President is willing to submit to questioning by Mueller on a limited number of topics.

The presidential call for such an investigation of the Department of Justice and the FBI, if taken seriously, would undoubtedly have required the appointment of a second independent counsel with Mueller-like powers to avoid a clear conflict of interest. This job is far too big for the DOJ inspector general's office which normally investigates relatively minor internal agency waste and misconduct claims.

Rosenstein may be hoping that the immediate inspector general referral will result in a swift investigation and closure of the matter. Part of the DOJ and the FBI 's job is after all the conduct of counterintelligence investigations and, if warranted by the evidence, the warning of presidential candidates that the Russians might try to infiltrate their campaigns to influence the American election. One would think that Trump would be grateful rather than suspicious about the warning.

Rosenstein's swift referral to the inspector general is unlikely to buy him much peace. Trump has repeatedly telegraphed his intense dislike for Rosenstein who, after all, is the person who appointed Mueller. Trump has previously attacked Inspector General Michael Horowitz , Rosenstein's choice for the investigation, calling him "Obama's guy," and criticizing a prior referral to the IG's Office by Jeff Sessions. Though widely respected as thorough and fair by those in the legal profession, Horowitz has no credibility with Trump.

In the end, Trump's attempt to embarrass his own Department of Justice and FBI is likely to wound only his own presidency. If Inspector General Horowitz makes the highly unlikely finding that the DOJ and the FBI acted criminally in their conduct of a counterintelligence operation related to the Trump campaign, a criminal referral will be necessary.

Since the DOJ can't prosecute itself, a new outside, independent counsel would have to be appointed as Mueller, too, would have a conflict of interest. Undoubtedly, some of the FISA warrants used to gather information in the early stages of his investigation were very likely supported by the counterintelligence operation now under investigation.

With the appointment of a new independent counsel whose job would necessarily include investigating the work of Mueller, the President will have created the bizarre spectacle of dueling independent counsels. In the firestorm which would follow, public confidence in the DOJ and the FBI would be shattered.

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Sunday's Twitter order to commence a new investigation to smear the Obama administration is likely to backfire and extend the Mueller investigation. It may also cause Mueller to look at an interesting new idea -- was the presidential order to commence such a frivolous investigation itself really an attempt to block the progress of the Mueller investigation and obstruct justice?

It might be the one piece of evidence needed by the independent counsel to prove corrupt intent as required by the obstruction of justice statute. The law of unintended consequences is a dangerous thing.