I Need Help With A Family Member But I Have No Proof

I would like to preface this that this is about my uncle. I HAD a trust fund, but I never received it. I know he took it along with my siblings as well. He also took the inheritance from my grandmother, a.k.a. his mom and my mom‘s mom. He also put his mother in a home to wouldn’t allow any visitors.!

My sibling and I went to visit her and just as we started to talk and all that after many years of not seeing each other, they came in and said that if we didn’t leave in the next two minutes that they were going to call the cops because we were not allowed to be there Broke my heart!

The other day, my dad was at Costco, saw him, called him out and chasing after him, and he ran away like a dog like a guilty dog with a tail between his legs like a wuss!! My uncle’s net worth is insane because of all the money he stole from my family from me and my sibling and probably other people too. I don’t know what to do!!!!

He also got a nice family deported back to Canada because the husband that he was working for him threatened to tell the cops of what my uncle was doing because he was doing some shady stuff so my uncle had them to my sibling because my sibling and their daughter were friends But they still didn’t deserve to be deported

I just wanna know how can I find a way to get my trust fund back because I had one and I never got it and I’m pretty sure when we went to go get it. We were told that the money was gone so there was only one person that we could think of that would’ve taken it , I don’t want to give his name out because I don’t want people to find out who I am but I need some legal advice on what to do because I talk to my dad about it and he said the first thing a lawyer is going to say is what proof do you have?

If anyone can tell me what to do because there’s no contact between us and it’s just sad that he had to steal from his although my sibling is non-binary now so I don’t know what to in terms of like nephew or whatever else but it just really sucks

TLDR : my uncle stole my siblings and my trust fund, but we don’t have proof. What do I do? What can I do?