Johnny Depp has to prove one thing to ensure his victory in the defamation case against Amber Heard.

More witnesses continue to take the stand in the defamation trial between Depp and Heard. The court has also heard and seen evidence that could help or break the actor in the end.

The "Pirates of the Caribbean" actor is suing his ex-wife over the 2018 op-ed she published in The Washington Post. Titled, "I spoke up against sexual violence - and faced our culture's wrath. That has to change," the piece is said to have affected Depp's career and led him to lose his major roles in different films.

Depp, however, is not mentioned in any part of the article. But his complaint suggested that it defamed his character - and continues to do so until now.

"The op-ed depended on the central premise that Ms. Heard was a domestic abuse victim and that Mr. Depp perpetrated domestic violence against her," Depp said.

Since Heard did not include his name, Depp received a countersuit from her. But the actor still has one move to take in order to secure his win.

What Johnny Depp Should Provide To Win Defamation Case

In a new piece shared by The Independent, it revealed that Depp and his team must show that Heard acted with "actual malice" as the actress allegedly defamed him thrice -- the print edition of the op-ed, one for its online edition, and one for when she tweeted the op-ed.

Professor of law and dean's distinguished scholar at the University of Miami School of Law, Lili Levi, explained it further to Poynter, explaining what it means for media law.

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"Actual malice for defamation law purposes means that the statement was made either with knowledge that it was false or with reckless disregard as to whether or not it was false," she said.

Meanwhile, entertainment litigator and defamation expert Daniel Gutenplan told People that the defamation is hard to prove. With that, the actor now finds himself in an uphill battle.

The trial already reached its Day 12, and Monday's arguments also suggested that Heard has been the perpetrator since the beginning. Before Heard takes the stand, the "Aquaman" star fired her PR team due to the changes in her public image amid the ongoing trial.

Heard is said to be upset about the coverage from the trial. She hired a new firm, Shane Communications.

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