Marine Corps Sgt. Andrew Tahmooressi served in one of Afghanistan’s deadliest provinces, but he never experienced horror until he took a wrong turn late at night last month and was dragged into a Mexican prison for the weapons he had in his car.

The 25-year-old decorated war veteran and Florida native was undergoing treatment for post-traumatic stress disorder at a veterans health care facility in San Diego when he inadvertently crossed an inspection station along the U.S.-Mexico border March 31, his mother, Jill Tahmooressi, told TheBlaze. Once he realized he was in the wrong lane, it was too late for him to turn around. He declared his weapons, but found himself in the grip of the Mexican federal agents.

This May 3, 2014, photo shows Sgt. Andrew Tahmooressi left, who is being held at Tijuana's La Mesa Penitentiary. The 25-year-old Marine Corps combat veteran is being held on weapons charges for mistakenly crossing the border with a shotgun, handgun and rifle in his vehicle. If Tahmooressi is convicted, he faces six to 21 years in a Mexican prison, his lawyers said, adding that alternatively the case could be dropped if the Mexican Attorney General’s Office in Mexico City requests dismissal. SAN DIEGO, ALEJANDRO TAMAYO — AP Photo

This May 3, 2014, photo shows Sgt. Andrew Tahmooressi left, who is being held at Tijuana’s La Mesa Penitentiary. The 25-year-old Marine Corps combat veteran is being held on weapons charges for mistakenly crossing the border with a shotgun, handgun and rifle in his vehicle. If Tahmooressi is convicted, he faces six to 21 years in a Mexican prison, his lawyers said, adding that alternatively the case could be dropped if the Mexican Attorney General’s Office in Mexico City requests dismissal. (AP Photo/Alejandro Tamayo)

Now, he’s facing up to 21 years in prison for the legally registered AR-15 rifle, .45-caliber pistol and 12-gauge pump shotgun he had in his car, along with the rest of his possessions.

Jill Tahmooressi said her son had only been in San Diego for 10 days and was looking for a place to live so he could continue treatment at the VA hospital. He was officially diagnosed with PTSD on March 25.

He narrowly escaped death those first few nights in Tijuana’s La Mesa Prison, his mother said. His only solace was a collect call he made to his mother the first night he was taken into custody.

Jill Tahmooressi said Andrew told her that “hit men” were threatening to rape, beat and kill him. He made her promise that if anything happened to him, she not go to the prison or question any of the Mexican authorities.

“He was afraid for my life more than his own and I never heard the fear like I heard in my son’s voice that night,” Jill Tahmooressi told TheBlaze through her tears. “The first few days when he was in the penitentiary he was not segregated and he’s a U.S. Marine currently under contract. He was placed in general population. His life was threatened and I really didn’t think after speaking with him that night that he would survive.”

But he did, and his mother said it’s due to his skills as a Marine: After being confronted in an open courtyard on the second day of his incarceration, he ran as fast as he could, scaling the corrugated steel barbed wire fence, narrowly escaping the men who wanted to kill him.

He was captured again by Mexican police, but it didn’t matter. His objective was to get away from the general population and for the next 30 days his arms and legs were shackled to a bed. The shackles were removed Friday, said his mother, who keeps in contact with him every day by phone.

U.S. Marine Sgt. Andrew P. Tahmooressi, a native of Ft. Lauderdale, Fla., and section leader with the 2nd Battalion, 6th Marine Regiment quick reaction force, is combat meritoriously promoted to his current rank here, Feb. 2. Tahmooressi received this meritorious promotion for the exemplary performance of his duties while holding the billet of a staff noncommissioned officer. Photo 1st Lt. Chris Harper, Pentagon.

U.S. Marine Sgt. Andrew Tahmooressi, a native of Ft. Lauderdale, Fla., was arrested in Mexico. (Photo courtesy of the Defense Video & Imagery Distribution System)

But time is running short. In less than a week, Mexican officials are scheduled to move Tahmooressi to a maximum-security prison about 40 miles outside of Tijuana.

According to the Miami Herald, which first reported Tahmooressi’s arrest, Mexican prosecutors have slapped three firearms charges on him, and his fate has been clouded by the wall-scaling escape attempt.

His mother is not giving up.

Tahmooressi, who survived a roadside bomb blast and concussion, was meritoriously promoted to his current rank as sergeant while deployed to Helmand province’s Nawa district, with the 2nd Battalion, 6th Marine Regiment.

“And he’ll survive this,” his mother said with pride in her voice.

She has received support from Florida Democrats Sen. Bill Nelson and Rep. Debbie Wasserman Schultz, but said her biggest help has come from Rep. Duncan Hunter (R-Calif.), whose district covers the border where Sgt. Tahmooressi crossed. Hunter sent a letter on Friday to Secretary of State John Kerry asking for his swift help in getting the Marine released.

“Andrew is neither a criminal nor a weapons trafficker, and his incarceration is an extraordinarily unfortunate occurrence,” Hunter wrote. “I am confident that this situation can be resolved quickly through the continued attention and support of the U.S. State Department, but I remain concerned for Andrew’s safety and well-being as a prisoner in Mexico. … Andrew was recently admitted to the prison infirmary with a reported knife wound to his neck.”

His mother said she would be spending Monday’s Cinco de Mayo holiday on the steps of the Mexican Consulate in Miami at a unity rally with supporters. She hopes people all across the country will contact the Mexican government and sign a petition on the White House website for her son’s release.

“He’s fighting for his freedom. He’s fighting for his life and he needs his country now,” Jill Tahmooressi said.

Another Florida Marine veteran was also held in a Mexican prison for four months in 2012 for carrying an antique shotgun in his motor home on his way to surf in Costa Rica. He was released after a very public campaign by lawmakers and the media.

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