Paper Trail, Tasers in Yacht Murder Case

Lewis said that he was on a trip with Jarvi and Deleon and that from his car, "I saw him [Deleon] escorting him [Jarvi] out of the vehicle. He had a blindfold or something over his head."

Getting a bad feeling about the situation, "I turned around and booked to get out of there," Lewis told the court. "Something's not cool," he recalled thinking. "I don't need to be here."

Though he sped away from the scene, Lewis said his cousin soon caught up with him.

"Next thing I know, my cousin is flying by me, he is making a [neck] snapping gesture," Lewis said. He added that a character in "The Long Kiss Goodnight," one of Deleon's favorite movies, used the same signal. "He was really into neck holds and anything of that nature," Lewis said of his cousin.

Matt Murphy, the senior deputy district attorney who is prosecuting the case, showed Lewis a photo of a dead body with a visibly slashed throat, lying in the dirt in a remote area. He identified the man as Jarvi.

"Skylar had mentioned to me that 'this guy had screwed him over before,'" Lewis testified.

After he allegedly murdered Jarvi, Deleon went to dinner with his cousin. "He mentioned I was on his side now, switching to the dark side," Lewis said.

But Pohlson, Deleon's defense attorney, pointed out that Lewis had served eight months in jail on an accessory charge related to the Jarvi case and that he previously had lied to investigators.

Lewis admitted to lying to authorities, but said it was because Deleon had threatened him.

"He's lying like crazy and his testimony made no sense," Pohlson told ABC News outside the courthouse, referring to Lewis' testimony.