Lock pick

Lock picks can be found in backpacks, breakable vases or in thin tall yellow lockers in camps around the map

they are a one time usage and can be used to unlock flare gun cases, medical supply cabinets and blue cases which usually contain a pistol if locked

you can also use them to unlock doors however it is not advised unless the door is metal as wooden doors can be broken down with melee attacks. Lockpicks are best saved for locked gun boxes.