Write SQL query to solve given problem: How many crime cases have been classified as "Weapons Violation" by the FBI?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT SUM(CASE WHEN T2.title = 'Weapons Violation' THEN 1 ELSE 0 END) FROM Crime AS T1 INNER JOIN FBI_Code AS T2 ON T1.fbi_code_no = T2.fbi_code_no