Among the top 5 owners with highest number of establishments, which owner has the highest number of high risk violations? Give the name of the owner.
5 owners with highest number of establishments refer to owner_name where MAX(COUNT(business_id)) LIMIT 5; the highest number of high risk violations refers to MAX(COUNT(risk_category = 'High Risk'));
SELECT T4.owner_name FROM violations AS T3 INNER JOIN businesses AS T4 ON T3.business_id = T4.business_id INNER JOIN ( SELECT T2.owner_name FROM violations AS T1 INNER JOIN businesses AS T2 ON T1.business_id = T2.business_id GROUP BY T2.owner_name ORDER BY COUNT(T1.business_id) DESC LIMIT 5 ) AS T5 ON T4.owner_name = T5.owner_name WHERE T3.risk_category = 'High Risk' GROUP BY T4.owner_name ORDER BY COUNT(T3.risk_category) DESC LIMIT 1