both
select staff_first_name, staff_last_name from staff as t1 join problem_log as t2 on t1.staff_id = t2.assigned_to_staff_id where t2.problem_id = 1
Now just list the staff who are assigned to problem id 1
select staff_first_name, staff_last_name from staff as t1 join problem_log as t2 on t1.staff_id = t2.assigned_to_staff_id where t2.problem_id = 1