Shortly after what many believe is Frank's death, Don Salieri asks Tommy to break into the Prosecutor's Villa, have the safe cracked by Salvatore, steal the evidence, and leave before the owner gets home.
After the cutscene, go visit Vincenzo and collect a Colt 1911 and a baseball bat. After you've collected your weapons, get a car and go out the doors. You must then drive to Hoboken and pick up Salvatore. Once you have completed that, drive to Oak Hill and get to the Prosecutor's villa. You will see a gate outside. Tell Salvatore to open it up and after that is done, just go in.
Get inside and then to the safe
First, move up a little and look to your left. Wait for the guard to turn around and quickly run to your right and move into that next pathway on your left that's lined with shrubs. Crouch and move forward. Keep an eye on the windows directly in your line of vision. The second you see the maid pass and turn off the last light run up the ramp to the house. Equip your bat, charge it up, hit the guard from behind, then take his shotgun and go inside.
Quickly go left and open the door, making sure to close it behind you. If you leave it open the maid will notice and call for the guards. Take the other door in here to go into the hallway and go right, then take the door on your left; you should now be in the stairway. Go up the stairs, turn left at the hallway, and go through the door in front of you. Crouch and open the other door in here, then go right and open the door in front of you in this hallway. Quickly take out your bat, knock her out, close the door behind you, and turn off the light. Crouch to the other door in the room and take the door in that room into the other hallway. Go right, open the door in front of you, and crouch walk to the safe. This will trigger a cutscene and a problem. Apparently the opera ended early and the Prosecutor came home way before he was supposed to. Now you must leave.
Go straight ahead, crouch walk down the stairs, and take the door in front of you. The maid will be very close, but it doesn't really matter if she sees you now. Go left at the end of the hallway and then head out the glass door. There's a guard out there and he is not far away from the door. You can kill him, but do so quietly. Have Salvatore open up the Prosecutor's car. Quickly get in since the guard usually notices you about now, and drive away. After you've made it out of the villa grounds, drive Salvatore home, which is near where you picked him up. After dropping him off drive back to the bar, completing the mission.
If you steal the Prosecutor's car, it will be added to your garage.
- During the briefing cutscene, Don Salieri says "...Paulie and Sam are taking care of the witnesses as we speak...", but if you check the briefing room after the cutscene ends, you will find Sam reading a magazine. This is a deleted and erroneous 'cue' for Sam in the PC version; however, it was fixed in the PS2/Xbox versions to Sam and Paulie interviewing one of the witnesses.
- Also if you talk to Sam after the cutscene in the PC version, he will answer you saying: "Go about your mission, it won't work.", suggesting that Sam may have talked with Don Salieri about the mission earlier and believes your mission to take the evidence would fail.
- In one of the bedrooms, a heart-jumping moment will happen when you stumble upon the Prosecutor's wife. She'll be sitting at a mirror and ask, "Hi, honey. Did you have a great day today?" However, she wears cucumbers in her eyes so she only assumes that you're the Prosecutor, and not an intruder.
- If you kill everyone at the beginning of the mission, the Prosecutor will flee from his villa upon arrival.
- No matter how long you wait The Prosecutor will not return home until you've opened the safe.