WESTON, Fla. -

After nearly two months in a Mexican jail facing weapons charges, U.S. Marine reservist Andrew Tahmooressi was finally brought before a judge Wednesday to explain how he accidentally crossed the border.

Details of Wednesday's courtroom proceedings remain scarce, but Tahmooressi fired his attorney, Alejandro Osuna.

"We do wish Andrew all the best, his family all the best, he's an innocent man, he shouldn't be here, and he'll get to the United States," said Osuna.

"He didn't have confidence in the first attorney," mother Jill Tahmooressi told Local 10 from her home in Weston. "I mean, there were red flags from the very beginning, but we were so vulnerable by being in a foreign country and a foreign judicial system."

The Tahmooressi family has already hired a new federal attorney who specializes in international criminal law. Family members are hopeful the judge will finally hear Tahmooressi's side of the story.

"Andrew was relieved and prepared to state the whole truth, nothing but the truth, so help me God, in that courtroom today," his mother said.

Thanks to public pressure, Andrew is now being held safely in a private cell isolated from the general population in a federal prison, but he is facing 4 1/2 to 21 years in a federal penitentiary if found guilty.

The border agents were expected to testify in court.

"We are hopeful they would be truthful and honest because Andrew clearly, clearly had the sense that the customs agents believed that he had made a mistake and ended up there accidentally," his mother said.

Tahmooressi, 25, was arrested in Tijuana, Mexico on April 1 as he was trying to cross the border. He was taken into custody when authorities discovered three guns in his car. It is illegal to bring firearms into Mexico.

He claims he took a wrong turn on his way to San Diego and accidentally crossed the border into Mexico.

A Marine veteran, also from South Florida, was held for four months in 2012 when he brought an antique firearm across the border.