Knight, 52, appeared in a Los Angeles courtroom on Thursday and denied the charges.
The former rap mogul smiled at his family in the front row of the courtroom.
His son wore a T-shirt that said, ‘FREE SUGE’, the LA Times reported.
He is accused of threatening Gray’s life in a text message while the film was being shot in August 2014.
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The alleged threat came just months before Suge was charged with murder over the death of a man in a parking lot in Compton in 2015.
Knight, who is currently in prison awaiting his murder trial, was indicted on felony criminal threats related to Gray earlier this year.
TMZ obtained a photo of Gray speaking to police on the set of Straight Outta Compton shortly after the alleged threat was made against him.
Knight, who started Death Row Records with Dr Dre after quitting NWA, was believed to have been angry with Gray about his portrayal in the film.