(CNN) -- A U.S. Marine sergeant jailed in Mexico since late March for crossing the border with several guns in his car said Friday that he had walked across the border on foot and stayed at a Tijuana hotel earlier on the day of his arrest.
Sgt. Andrew Tahmooressi, who also said he attempted suicide while being abused by his Mexican jailers, has maintained that he took a wrong turn on the California side of the border, his vehicle carrying firearms he said he legally owns but are unlawful to bring into Mexico.
"I stayed in a hotel earlier in the day," Tahmooressi said Friday in an interview with CNN's "New Day."
"I parked my truck at a parking lot on the American side ... and I walk into Mexico with a backpack with extra clothes and hygiene supplies, passport, wallet. And I decide to go hang out in Mexico for some good Mexican food, inexpensive place to stay and to hang out."
Asked about Mexican media reports that he had crossed the border into Mexico several times before his March 31 arrest, Tahmooressi told CNN in a telephone interview from La Mesa penitentiary in Tijuana that he had previously traveled there four times "just to hang out."
He denied crossing the border with the intent of trafficking arms. He had an AR-15 rifle, a .45-caliber pistol and a 12-gauge pump shotgun in his truck.
"I know what they're going to say," Tahmooressi said of Mexican authorities. "They're going to say a whole bunch of lies. They're already saying a whole bunch of lies. I just know that the truth will set me free."
An Afghanistan war veteran, Tahmooressi, 25, had recently moved to Southern California to get treatment for post-traumatic stress disorder, according to his family.
Tahmooressi described a suicide attempt with a shattered light bulb after being punched, slapped, cursed at, deprived of water and food, and shackled to a bed with a four-point restraint in a Mexican prison.
"I had one hand above my head, not both, just one," he told CNN. "I was laying on a bed. ... When I got the opportunity, I decided to stab myself in the neck with a light bulb ... I was paranoid. I had been abused. I was thinking they were going to come and abuse me more and torture me and get information about my family from me. So I said, 'I'm not going to allow them to do that.' "
Tahmooressi said conditions improved after media coverage of his plight. Mexican prison authorities have denied the abuse allegations.
"I would like everyone to know that I'm an innocent man and that it was just a big mistake and that I had no intention of bringing weapons into Mexico or committing any crime at all," he said. "Unfortunately, I wasn't treated right at the border and my rights were violated."
His mother, Jill Tahmooressi, last week said her son's next court hearing is weeks away.
She has said her son immediately disclosed to the border guards that he had weapons and requested that he be allowed to turn around.
A 911 tape released by U.S. Rep. Duncan Hunter, R-California, appears to support the Marine's version of events.
In it, the Marine is heard saying, "I crossed the border by accident, and I have three guns in my truck, and they're trying to take my guns from me."
After learning he was in Mexico, the 911 dispatcher responded: "There's nothing I can help you with then, sir. I do apologize. You're not on American soil anymore."
Tahmooressi asked whether authorities have a right to take his guns.
The dispatcher said he should have seen large warning signs on the freeway saying it's illegal to enter Mexico with guns.
"There are warning signs that do say that as you're driving down the freeway, before you enter Mexico," she said.
"Yeah, I was hoping there would be a turnaround point," he responded, "but there never was."
His mother has said Tahmooressi was searching for permanent housing and often stayed in San Diego hotels.
U.S. Secretary of State John Kerry told CNN last month that he had spoken with Mexican authorities about the veteran's case.
Tahmooressi's family and friends also pressed their case in a White House petition that had more than 122,000 signatures -- above the mark needed to garner an official government response.
"I don't know what they're going to do to help me," he said. "If they do help me, it's probably just going to be behind the scenes and the public isn't going to know about it."
CNN's Nick Valencia, Jason Morris and Holly Yan contributed to this report.