Trustee Bank Accounts When One Trustee Takes Money Out Of Deceased Bank Account With Out The Other Trustee Knowing What Do I Do?

When one trustee takes money out of deceased bank account with out the other trustee knowing what do i do? - trustee bank accounts

My sister and I are an administrator for the account of my late mother, the POA had to pay before his death, to all accounts my mother, I was just found out money for his personal use past 2 years, I have a large sum of money,