Who is the alderman in the ward associated with the crime with report number 23769?
alderman refers to alderman_suffix, alderman_first_name, alderman_last_name; report number 23769 refers to report_no = 23769
SELECT T2.alderman_first_name, T2.alderman_last_name FROM Crime AS T1 INNER JOIN Ward AS T2 ON T2.ward_no = T1.ward_no WHERE T1.report_no = 23769