"It was not surprising to be seen with suspicion as I walked the streets of Cova da Moura. I was a stranger and although no one directly asked if I was a cop, clearly they wondered. Why was I so interested in the daily life there, if it were not to inform on them?

This little enclave of Cape Verde islanders on the outskirts of Lisbon has a strong sense of community. I think of streets as public spaces, but in Cova they are private domains. Each corner has a distinct personality. Certain crossroads are to be avoided.

As I wandered around, I felt the stare of eyes from apartments above,...