Legal experts said Trump's phone call to a January 6 witness isn't enough to charge him with a federal crime yet, but could be a tantalizing 'teaser' of what's to come

• Donald Trump is accused of trying to call a witness in January.

• The matter was referred to the US Department of Justice.

• There needs to be more evidence for witness tampering charges.

The House select committee investigating the Capitol riot has referred Donald Trump's attempt to speak with one of the witnesses to the US Department of Justice.

It would be hard to prove that a call is illegal tampering with a witness.

Peter Zeidenberg, who served on the Justice Department's special-prosecution team during the George W. Bush era, told Insider that Trump is lucky that the witness did not answer the phone. If he spoke with the witness, that could have been a big issue. I don't believe much can be done. It's the kind of thing that frightens the defense attorneys.

"After our last hearing, President Trump tried to call a witness in our investigation," Cheney said at the end of the hearing. The person refused to answer the phone and instead called their lawyer.

The committee gave the information to the Department of Justice, according to Cheney. Evidence was shared in June that those in Trump's inner circle were trying to influence testimony.

Federal law forbids the use of intimidation in official proceedings. If a person is convicted of harassing a witness, they can be fined and imprisoned for as long as three years.

The revelation may have come early for the prosecutors, according to a former federal prosecutor. Trump is a subject of both the committee's and Justice Department's investigations, and now is accused of trying to influence testimony.

According to Insider, a former prosecutor with the US Attorney's Office for the Northern District of Illinois, Cheney was smart to put down a marker and warn Trump not to tampering with a witness. He said the evidence she presented was not enough to support a criminal prosecution.

He said that a phone call that didn't happen is not enough for a witness-tampering charge.

William Jeffries was a white-collar attorney who represented former President Richard Nixon.

Jeffries told Insider that contacting a witness in advance of his or her testimony is not a good idea.

It would be an understatement to say that Trump's attempt to speak to a witness was dumb.

He has exposed himself to criminal charges of witness tampering and obstruction of Congress.

The former US attorney for the Northern District of Alabama said that the call was not necessarily legal.

She said that the statute prohibits witness tampering. "Bringing a charge is dependent on how good the evidence is."

The US Department of Justice suggests that an unanswered phone call can be used to make a crime out of it.

It says there is no requirement that the actions of the defendants have the intended effect.

Andrew McCarthy is a former federal prosecutor who writes for the conservative National Review. He criticized the committee for floating an insinuation of a felony.

Philip Allen Lacovara, a former counsel for the Watergate prosecution team, referred to Cheney's comments Tuesday as a "teaser" and said he thought there was more to come. The hearing is expected to be held in the evening.

He said that if the narrator mentions a gun on page three, someone has to be shot by page six. He mentioned the gun. Don't be surprised."

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