Ex-Marine Jon Hammar Freed From Mexico Prison

Dec. 22, 2012— -- A former U.S. Marine has been released from a Mexico jail after being locked up for five months on gun charges.

Officials from the U.S. Consulate General in Matamoros, Mexico met Jon Hammar at the prison Friday and escorted him to the U.S. border, where he was reunited with his family in time for the holidays, said Patrick Ventrell, acting deputy spokesperson for the U.S. State Department.

The nightmare unfolded in August, when Hammar and fellow veteran Ian McDonough departed for what was supposed to be a few months of surfing and camping in a Winnebago in Costa Rica.

The two had recently finished a treatment program for post-traumatic stress disorder, which Hammar suffered after fighting in Fallujah, Afghanistan, according to his mother, Olivia Hammar.

"The treatment's very exhausting, it's a tough program, and he was there almost nine months," said Olivia Hammar. "(They) decided they were going to buy an R.V., fix it up, drive down to Costa Rica through Mexico, and we were very nervous about it. We tried to discourage it, to tell him to take a plane, but they said, 'We're taking nine surfboards and need a place to stay.'"

Hammar and McDonough arrived on the border between Mexico and Texas on Aug. 15. Hammar, however, had packed his great grandfather's shotgun, a .410 Sears and Roebuck model nearly 100 years old. Hammar had hoped to hunt small birds with it while living in Costa Rica, Olivia said. The pair wanted to register the gun with Mexican authorities at the crossing point.

"There were signs that said you can't take a firearm, and so Ian said scrap it, don't take it, but Johnny said, 'Let's talk to the customs agent,'" according to Olivia. "They said, 'Technically you can (bring it across) but you'll need to register it,' and had (Johnny) fill out paperwork to present to Mexican officials."

The gun was meant for hunting, but border officials arrested the pair on federal charges of having a weapon that is reserved for military use. McDonough was released when Hammar claimed the gun was his.

Olivia and Jon Hammar, Sr., hired local lawyers to defend their son in Matamoros, Mexico, where Hammar was taken to state prison. The U.S. State Department was notified by Mexican authorities the following day, according to a department official who spoke on background.

"Almost immediately we began receiving extortion calls from cartel members in prison with him," Olivia said. The State Department and Hammar's lawyer, Eddie Varon Levy, would not comment on the claim about cartel members.

"They're saying, 'You need to wire us money or we're going to kill your son, we've already f---ed him up,' and initially I thought it was a scam, but then they put him on the phone and he was breathless and I knew they had," Olivia said. "He said, 'You need to do whatever they say. I'm so sorry. I'll pay you back.'"

Hammar had been a lifelong surfer and sailor who loved being outdoors. He enlisted in the Marines at age 18, in 2003, to challenge himself. When he returned from his second tour of duty in Afghanistan in 2007, after his unit lost 16 soldiers, he was "a different man," she said.

Hammar's release was celebrated by U.S. Rep. Ileana Ros-Lehtinen, who was one of his most vocial supporters.

"I am overcome with joy knowing that Jon will be spending Christmas with his parents, family and friends," she said.

ABC News' Alyssa Newcomb contributed to this report