More than a month ago Sgt. Andrew Tahmooressi, a U.S. Marine and Afghanistan war veteran, was arrested by Mexican authorities on weapons charges and has been held in a Tijuana, Mexico prison since.

Tahmooressi said he was on his way to meet friends in San Ysidro, California on March 31 at around 10 p.m. when he accidentally crossed the U.S.-Mexico border while he was carrying three personal firearms, CNN reported.

"I accidentally drove into Mexico with three guns ... a rifle (AR-15), a .45 cal pistol and a 12 gauge pump shotgun with no intensions [sic] on being in Mexico or being involved in any criminal activities," Tahmooressi wrote in a statement of innocence to U.S. Rep Duncan Hunter. "I have rights to all three weapons. They are under my name ... Please help me."

The 25-year-old's mother, Jill, told CNN he was "essentially living out of his truck" near the area so he could receive treatment for post-traumatic stress disorder.

According to the Mexican attorney general's office, Tahmooressi, who is being held at La Mesa penitentiary in Tijuana, awaits his court date set for May 28.

Hunter, a California Republican, has lead a petition to get Tahmooressi released and wrote a letter to both Secretary of State John Kerry last week in which he urged him to get involved.

He also wrote a bipartisan congressional letter to Mexico's attorney general on May 8.

"Mexico's Attorney General is in a position to deal with Andrew's case and ensure its quick resolution ... it is necessary that the AG intervene and expedite proceedings at the very least. And so far there's been no validation from Mexico that Andrew didn't make a directional mistake at the border."

Jill, who has been fighting for her son's release, said in an interview in Miami that she wished to see Tahmooressi for Mother's Day, which just passed.

"Mother's Day is Sunday. If I can have my baby home on Sunday that would be the greatest gift a mother could ever ask for," Jill said. "The brutality of being ... unjustly in a foreign prison is worse than any experience I had with him serving two tours in Afghanistan. He was willing to die for his country as a Marine. Where is his country now when he needs it the most?"