I have a continuing problem with my brother. I have POA and care for my Mom. He lives three states away. Is he committing fraud?

He continually trys to figure out how to take over my moms care, undermines me, and constantly asked where the money is. Today he used a medical directive that he had my mom sign AFTER she was deemed unable to make her own decisions. He used it to try to obtain financial information regarding the sale of one of mom's properties. Is this fraud? Can I have him charged? He knew that mom my has dementia and that she was deemed incompetent.