I voted for Tessio - he was such an important member of the family and went way back to the early days with Vito it was 'shocking'! When he's about to be taken away and he asks Tom for help was really touching - Tom seemed really saddened by it.
TPM

"My wife was weeping before she fell asleep, outside my window I saw my Caporegimes coming to the house and it is midnight. So, Consigliori of mine, I think you should tell your Don what everyone knows."