Washington (CNN) Federal prosecutors can't show a clip from the film "The Godfather Part II" at a trial as they try to prove to a jury that Roger Stone threatened a witness, a federal judge said Monday.

Judge Amy Berman Jackson of the federal district court in Washington said showing the clip -- which prosecutors wanted to do because Stone referred to it in a conversation with his associate Randy Credico, whom he allegedly threatened -- could prejudice the jury.

They can't show it "because the prejudicial effect of the videotape, which includes a number of extraneous matters, outweighs its probative value," she wrote.

The jury will be able to see a transcript of the relevant scene in the movie, Jackson said.

And it's possible prosecutors could ask her again to consider showing a clip from the film after Credico testifies or if Stone takes the stand, she said.

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