You may contact the Campus Security to request access to campus surveillance tapes. Then file a report with the Student Assistance Division and the General Services Division (the General Services Division of the Office of General Affairs is responsible for managing stray dogs found on campus, so they may be able to help you).
Campus Security：02-3366-2185或02-3366-2186，地圖
Student Assistance Division：02-3366-2048，地圖
General Services Division：02-3366-2234，地圖