You need to be sensitive to tiny details

People usually give me a thumbs-up when they hear I've solved more than 300 cases in the past eight years, and they then tell me how hard it must be to be a police officer. But there is something also special about this job.

For a start, you need to be sensitive to tiny details.

In July 2013, I was assigned to look into a series of arson attacks on five newsstands across Zhongguancun, a busy part of Haidian district, which had all occurred in the same month. I visited business owners and residents, but there was little to go on.