Two issues in the OP. First, why would a member of law enforcement be making a cash deposit to an account of a law firm? That part is more than puzzling.
But, since the deposit was made to the IOLTA, the law firm and its client(s) on whose behalf the cash was deposited at named in the CTR. And, since a CTR is filed, the member of LE should be identified as the transactor, using his LE ID info.
John S. Burnett
Fighting for Compliance since 1976
Bankers' Threads User #8