In the following days, they were spent boringly in the investigation of the case.
Each team conducted their investigations according to the established goals, Liu Jinghui redid the timetables for several key individuals, and Jiang Yuan started receiving more and more trace evidence reports, which he found very compelling.
Using trace evidence in investigation is a rather luxurious matter, as the general criminal investigation teams only resort to it in major cases on key pieces of evidence. It's not that they can't afford the 500 yuan, but rather that DNA has a better cost-performance ratio.
Unlike DNA evidence, even if conclusions about trace evidence are drawn, they can only indicate that certain substances were present at a certain place and time; there's still a considerable distance to go before solving the case.
By contrast, if someone's DNA is found at the crime scene, there must be an explanation.
