(CNN) - A U.S Marine Corps Reservist is speaking out from his jail cell in Mexico on Sunday, again proclaiming his innocence.
Sgt. Andrew Tahmooressi says he's hopeful and optimistic that he might go free soon. There's a court hearing in his case this week.
Tahmooressi was arrested after driving into Mexico with three firearms in his truck: a 45-caliber pistol, a 12-gauge pump shotgun and an AR-15 rifle.
He maintains he took a wrong turn on the California side of the border into Tijuana, Mexico, the night of March 31.
"I'm not a guilty man, and you can probably hear it from my voice and the sincerity in my voice,” Tahmooressi said to CNN Sunday by phone from the prison in Tecate, Mexico.
“I'm innocent, and it was just big mistake,” he explained. “I never meant to be in Mexico. I wouldn't go about trying to sell my guns to criminals. For one, I'm not a criminal, and I don't like any criminal activity. I especially don't like any cartel people.”
Tahmooressi said he feels like the punishment wasn’t necessary.
“I made it very obvious that it was a mistake for me to be here,” he said. “They even told me that they were going to escort me back to America, but once the [Mexican] military people got involved, they were like, 'Look what we found, we found these guns, good for us. Let's get this guy incriminated.' I don't think I deserve any punishment and I definitely don't deserve any more punishment. I deserve to be set free because I'm not a criminal."
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