The attorney for Sgt. Andrew Tahmooressi, who remains jailed in Mexico on gun charges, said Tuesday that he plans to file a motion next week to throw out evidence obtained in the early hours of the Marine's arrest.
Fernando Benitez said the motion will claim that Tahmooressi was denied his civil rights after his eight-hour detainment on March 31 because he wasn't given a translator to adequately explain why he was being arrested. The Marine has remained in Mexican custody since late March, when he accidentally drove into the country with three legally purchased firearms after he made a wrong turn.
Benitez added that not only would the motion, which he called "extraordinary," render the prosecution's evidence useless, but would effectively release Tahmooressi from prison.
The remarks on Tuesday represent a change from recent statements by Benitez, in which he said the trial would continue even if certain evidence was thrown out.
He said he will file the motion early next week, at which time a hearing will be set within 10 days. Once the hearing is held, a decision would be made by the judge within three days, Benitez said.
"Even if it ultimately does not result in the declaration of a mistrial, it will give us grounds for an appeal and a constitutional review," Benitez said. "It would be an excuse to get this to a higher court."
Also on Tuesday, Benitez said Tahmooressi's failed attempt to "escape" from the La Mesa prison early in his detainment was due to fears that his life was in danger and that he merely tried to move from one holding area of the prison to another.
"He tried and succeeded to get from one holding area to another," Benitez said. "That's the escape attempt."
Tahmooressi made a court appearance on Monday, during which he faced four border officials who were involved in his arrest. Benitez told Fox News' Greta Van Susteren that the Marine was "a little more upbeat" and was growing more optimistic about his case.
But Jill Tahooressi, Andrew's mother, told Van Susteren on Tuesday that she's worried that the case could drag on for months -- and that she's not sure if the Marine, a combat veteran who suffers from post-traumatic stress disorder, can handle the prospect of many more months in Mexican custody.
"I'm afraid to let him know that I might have to possibly buy him a winter coat to prepare him for Christmas," Jill Tahmooressi said. "I don't have the heart to do that. Mentally, I don't believe he can take that news right now."
Fox News' Dan Gallo and Joseph J. Kolb contributed to this report.