Below are the solutions to all the locks and safes in the game and where the combination to them is found. I've laid these out in roughly the order you come across the lock as you progress in the story
Police Station:
- Lion Statue Lock Solution (Lobby, 2F) - Lion, Branch, Bird
- Rookie's First Assignment Initials (West Office, 1F) - Left Lock: NED, Right Lock: MRG
- West Office Safe (West Office, 1F) - Left 9, Right 15, Left 7 - Found in S.T.A.R.S. Office memo.
- Men's Locker Room Dial Lock (West wing, 2F) - CAP - Found in note in room attached to Operations Room.
- 3F Stairs Dial Lock (west wing, 3F) - DCM - Found in a film roll
- Unicorn Statue Lock Solution (West wing, 2F, Lounge behind Library) - Fish, Scorpion, Vase
- Waiting Room Safe (East wing, 2F, through the Spade door) - Left 6, Right 2, Left 11 - Found in Confiscation Report File
- Maiden Statue Lock Solution (West wing, 3F, in store room above Library) - Woman, Bow, Snake
Sewers:
- Sewer Control Room Dial Lock - SZF - Found in Jazz Festival Flyer
- Treatment Pool Room Safe - Left 2, Right 12, Left 8 - Found on side of the safe
Underground Lab (NEST):
- Greenhouse Control Room Ladder Code 1 Solution - "F" looking symbol, II, two small L shapes (one on top of the other), "F" symbol - Found on ladder hatch top in the greenhouse
- Greenhouse Control Room Drug Testing Code 2 Solution - Two small L shapes (one on top of the other), I, a big square above a little square, and a thicker I - Found on base of a trophy from East area Lounge