Resident Evil has always been home to multiple keys and locked doors. Without collecting all the keys, you can rarely get all the best gear. Check out this Resident Evil 2 key location guide to find them all as you play the game.
Resident Evil 2 Key Location Guide
You can find the Weapon Locker here on the map, on the west side of the Police Station.
When you are in the parking garage, examine the key and click the buttons to open the trunk on a car. You will get different items depending on who you are playing as.
You will have to pull out a corpse to get the key and when you collect it the zombies will wake up.
It is strapped to a white board, grab it before you leave.