Eric Trump breaks judge's rules by attacking witness Michael Cohen from courtroom

Eric Trump was seen using his cell phone in a Manhattan courtroom after New York Justice Juan Merchan forbade using mobile devices.

NBC News reported that Eric Trump was sitting behind his father when he wrote a message on the social media platform formerly known as Twitter.

"I have never seen anything more rehearsed," he said of Michael Cohen's testimony.

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"The court does not allow anyone in the courtroom to use their cellphones during proceedings," NBC News noted.

Merchan has also ordered Donald Trump not to cause anyone to discuss potential witnesses in the case. It was not clear if Eric Trump broke that rule.

Eric Trump is the only family member of Donald Trump to appear in the courtroom.