Database: chicago_crime
Question: Tell the number of cases with arrests in North Lawndale community.
SQL: SELECT SUM(CASE WHEN T1.community_area_name = 'North Lawndale' THEN 1 ELSE 0 END) FROM Community_Area AS T1 INNER JOIN Crime AS T2 ON T1.community_area_no = T2.community_area_no WHERE T2.arrest = 'TRUE'