Can a employment lawyer help me if I was falsely accused

I was falsely accused for some thing I did not do. I saw the person that did the act. The manager falsely accused me of stealing gas from the companies gas card I told them who was taking the gas card every other day to fill there car up. The person work at the same company and he was an site supervisor that stole the gas from the company gas card. When I ask him he told me that the gave him permission to use the gas card. So he would get it his self and drive his truck to the gas station and fill up while I was at the job site because I can not move the security truck for no reason at all unless the walmart managers tell me to. so thats what I told chris the manager that falsely accused me this so how could I use the card if I can not leave from the truck I told that their's proof on the camera at cheveron where he use the card.