Courtyard
You will find it by using our walkthrough for this mission. You'll make your way through some tunnels and then come up to a parking lot with several cop cars. The evidence is on the hood of the middle car. It isn't particularly hard to scoot over to the hood as long as you move quickly.
Vixen Club
You will find it by using our walkthrough for this mission. Depending on how you came into the Vixen Club itself, you may have found it almost immediately. From the outside of the club, instead of going in the front door, climb up to the ledge from the left side and climb through the window. The evidence will be on a table in this room.
Derelict Building
You will find it by using our walkthrough for this mission. When you move through the derelict building, you can go upstairs (and will using the walkthrough). There will be a section where you go through a long hallway and can drop off at the end. This will leave you where the cops have their impromptu meeting. As soon as you drop off that ledge, you'll land on the evidence and you merely need to pick it up.
Convenience Store
You will find it by using our walkthrough for this mission. After setting off the fire alarm to distract the guards inside the convenience store, you need to make your way to the front door. To the right of the front door will be a check out station. The evidence is on the other side of the counter. You need to sneak in and grab it. On normal, if you tuck into the counter, you can't be seen even by the guard who walks a patrol along this wall. Timing is crucial, however.
Loading Area
You will find it by using our walkthrough for this mission. When you enter the loading area, if you hug the left side then you will be able to go up some stairs into a small office. The evidence is on a table across from the door you just came through.
Chinese New Year
You will find it by using our walkthrough for this mission. The evidence in this location is a new area that wasn't accessible during your last trip to Chinatown. Starting from where you entered Chinatown last time (from the alley and through the two large red doors), go forward a little and you'll see an alley guarded by a cop on your left. The evidence is just past this cop on the ground. You may need a distraction or disguise to get through to it.
