I have been battling my uncle in probate court for 2 and 1/2 years and finally had him removed as the executor to my grandmothers Trust. The court has appointed a new executor and ordered my uncle to turn over all the books and assets to the new executor.

So he went to the bank where the trust was held, and took out the $321,000.00 held in that trust and put it into a Bank account under his name, leaving the trust account closed. When does that become criminal. What should I do next?

That became criminal when he put it in his name alone. The new executor should first have the court put a freeze on the bank account, and notify the DA of the theft.

Was his name solely on this trust account

No he was the trustee when my Grandmother passed away. There are 4 beneficiaries to the trust and he was removed as trustee on July 18th 2007, by court order. On the 19th he went to the Bank and closed the account in the name of the trust. Took the cashiers check to another Bank and opened a new account under his name and social security number. And refuses to turn over the assets to the new court appointed executor

Wow perhaps the bank it self could be able to assist you they to could be at fault

You definitely should hire a good estate lawyer. The cost could come out of the estate money. The lawyer will make sure everything is correct