谢谢老猫，码这么长的中文还是蛮辛苦的！

分析的很全面！给了我一个错觉以为老猫就工作在这个部门，因为他们（包括主任）就是这么拒绝我要查看的要求的。他们也不愿意release在那可疑录像段时间内上机的那个学生的ID. (so I quickly conclude the student is not a minority in high chance).

I behaved very good in all contacts with the authorities, in the end, I couldn't find it. I filed a police report. I will update you in how low efficiency the policeman will handle the case with a "sorry" in the end, possibily 2 months later. I swear here that I will be very polite and contructive in communicating with the authority.