There have been quite a few reports recently that wanted criminals were captured because of this technology. Some of those had been escaping from police for many years. It’s about capturing criminals not detecting suspects.

Most interestingly, it happened several times that criminals were caught during watching Zhang Xueyou’s (a pop star) concert. An article mentioning that:

https://qz.com/1285912/chinas-facial-recognition-cameras-kee...

A recent article did some stats and claimed that a total of 55 criminals were captured at Zhang Xueyou's concert. http://www.chinanews.com/sh/2018/10-24/8658284.shtml