My uncle stole my inheritance. What can I do?

When I was just 20 my parents died in a car crash in 1999. A month or two later, my uncle quickly went to a lawyer and had my grandmother (who was in living in a nursing home) rewrite her will so that my mother would inherit nothing and he would inherit everything. I remember my mother telling me that my grandmother was senile many different times. I remember her acting very senile and not herself too. How can he get away with taking advantage of my grandmother and falsely claiming she was of sound mind when he coaxed her to change the will at the age of 88. Anyway, when my parents had just died my uncle was extra friendly, giving me very strange inappropriate hugs and being extra nice. He had never been nice before this. Then after a certain number of years he quickly stopped being so friendly. I think he was acting extra nice so that I would not go after him in court. He even told me that the land that he had stolen from me by changing the will was mine too. But once he figured enough years had passed by for him to get away with everything he became very nasty and pretended he never told me this. What can I do about this crook? Shouldn't he go to jail for stealing my inheritance???