Why would you think the person would have social media (or would even be on Chinese social media specifically), given the sophistication and planning?

I mention Chinese social media specifically because I know it's not indexed so well by western search engines. You can't conclude someone has no social footprint until you've actually checked.

Regardless of how likely you think it is, finding a social media footprint would be useful information. Seek information first, reach conclusions second.

I found this link on Zhihu: https://www.zhihu.com/question/650826484