I moved into an apartment complex where the key is both unique to each apartment door, but every key can open the front door, how are both possible?

Question

I moved into an apartment complex where the key is both unique to each apartment door, but every key can open the front door, how are both possible?

In: 986

Answer 1

The outer doors, are usually simpler locks (fewer pins)

At the apartment complex I rented.. the outer door was a 2 pin lock. The inners where more.

But that allowed every key to open the outer door.

It was also easily picked. And the camera that faces the sun every morning, could barely pick up shapes. But they got to list them as security features.