This statement appears in paragraph (4) in the Watchtower letter above, and I thought that was what he was looking for. If not, I'll keep looking.
************************************************************************************
There is one exception to the above direction: The elders may have written to the branch office and given full details about a former child abuser who is currently serving as an elder or ministerial servant. In such a case, if the branch office has decided that he can be appointed or continue serving in a position of trust because the sin occurred many years ago and because he has lived an exemplary life since then, his name should not appear on the List, nor is it necessary to pass on information about the brother?s past sin if he moves to another congregation unless contrary instructions have been given by the branch. If therefore, such an appointed man moves to another congregation a letter confirming the move should be sent, addressed to the Society?s Legal Department.