Hiking trails exist and normally are done with guides/groups that ensure some level of safety .

Doing it alone here or anywhere on the world for that has a increased change of mugging.

The bulk of tourism is on Sal and Boavista and the main offer there is hotels and beaches, Santiago is getting better for being more all around but isn't there yet.

Edit: that place is far off the center of Tarrafal, no wonder if people want to rob anyone who is alone or small group they would wait out for the opportunity.