Whether you're playing as Leon or Claire, the solutions remain the same and can be accessed without grabbing the memo that hints at their solution. The only exception to this are the items you grab by developing film rolls--though, there is a minor exception even to that. Regardless, below you can find details on all the optional items locked behind safes, lockers, or hidden in the environment.
The storage lockers were a “pilot,” the kind of small test that city government frequently uses to test a new or controversial idea. The city offered up the lockers for individuals to use for months-long stretches. At the time, city officials warned that “misuse of the lockers, vandalism, or other unanticipated results,” could force them to cancel the project.