( CNN ) -- U.S. Marine Corps reservist Sgt . Andrew Tahmooressi told CNN by phone Sunday that he was `` more hopeful '' and `` optimistic '' than ever that he would be released from a Mexican prison after a court hearing coming on Wednesday . More than three months after he was imprisoned for driving into Mexico with three firearms in his truck , Tahmooressi called CNN from the El Hongo Penitentiary in Tecate , Mexico , where he is being held . `` I 'm not as down as I once was , '' he said . `` My relationship with the guards has turned more into a friendship , so I do n't feel as alone , I guess . Once the media started covering it ... things did start changing . ... I 'm just trying to keep my cool and stay relaxed . '' Tahmooressi has maintained that he took a wrong turn on the California side of the border into Tijuana , Mexico , the night of March 31 . He was detained by Mexican border officials for possessing a .45-caliber pistol , a 12-gauge pump shotgun and an AR-15 rifle . `` I 'm not a guilty man , and you can probably hear it from my voice and the sincerity in my voice , '' he said . `` I 'm innocent , and it was just a big mistake . '' He says he replays in his head what happened the night he was arrested . Tahmooressi has denied crossing the border with the intent of trafficking arms . He said allegations against him that he could be involved with in gun trafficking or anything nefarious are `` silly . '' `` I do n't know what more there is to say , really , '' Tahmooressi said when asked what he would tell people who do n't believe what he did was an accident . `` If you look at the facts , I mean ... I 'm a smart man too , I 'd like to think . I would n't go about trying to sell my guns to criminals . For one , I 'm not a criminal . And I do n't like any criminal activity . I especially do n't like any cartel people . '' `` I would n't have gone about selling my guns to get money . I would have sold my motorcycle . I would have sold my truck . Besides that I had plenty of money in my bank account that I had saved up from the Marine Corps . And I 'm not a dumb man , to be selling my guns that have serial numbers registered to me . '' The director of the Tijuana checkpoint told Mexican media last month that Mexican agents at the border gave Tahmooressi a chance to surrender his weapons and return to the United States without incident . Tahmooressi told CNN that 's `` a lie . '' `` That 's not true at all . They never told me anything of that sort , '' he said . Tahmooressi said the Spanish translator provided to him at the border added to the confusion in communication . `` After I had got off the phone with 911 and I felt like there was no one there to help me , I even told them , I said , 'You can take my guns , take my truck and take all my possessions , just let me go back to America . ' And they shook their head no in frustration . '' Asked by CNN if he believes he should receive punishment for his mistake , Tahmooressi said no . `` I feel like the punishment was never necessary from the beginning . But once the ( Mexican ) military people got involved , they were like , 'Look what we found , we found these guns , good for us . Let 's get this guy incriminated . ' There was some good people at the border who were going to do the right thing , and that 's how it should have been from the start . '' As for what he needs most right now , Tahmooressi said , `` I just need the people to keep on praying for me . I think that should help . There 's really nothing else besides that that I need , '' he said . `` My court date is on Wednesday . Once the judge gets to hear me out , I think it should go well . And I think it should n't be too much longer ( that I will be in prison ) after that , I hope . '' Marine says he 'd walked into Mexico before his arrest on gun charges . Opinion : Should Marine be in Mexican prison ?
' I 'm not as down as I once was , '' Sgt . Tahmooressi tells Sgt . He hopes Wednesday hearing will bring his release from prison where he 's spent Wednesday . Tahmooressi was arrested in March for crossing into Tahmooressi with 911 firearms . He says he took a wrong turn and would never consider trafficking in guns .