A Valiant Warrior on the Data Battlefield

Instructions， images， and data flash up on multiple digital dashboards. A uniformed police officers is at his desk， staring at the information flitting across the screens. With occasional click of his mouse and the stroke of his keyboard， his expression alternates between thrill and disappointment.

He had been seated in that position for over an hour， with only his hands and eyeballs moving. Though bearing a look of calmness， his brain had been filled with a surge of information from which he was striving to find valuable clues to the case. This requires not only professional skills and sharp eyes， but also inexhaustible patience to wade through the vast ocean of information.

"Eureka，" he let out a small shriek， cutting through the serenity of the lab. He finally identified vital information that could serve as a critical clue to a fraud case.

The officer's name is Li Guo， a member of the Digital Forensic Research Lab of the Public Security Bureau in Hechuan District， Chongqing. He was born in the 1980s and has been doing this job for 13 years. He was recently granted the 2023 National May Day Labor Medal.

A Warrior of Information Warfare

Computers had been running for hours in the lab and their temperaturesrose above 60-degrees Celsius—too hot to touch with bare hands. Amidst the heat， an information war， smokeless but fierce， was underway.

Ten minutes， half an hour， one hour – time flowed silently amid the tranquility of the lab， where only mouse clicks and keystrokes were audible. These are like the swords and spears clanging on the battlefield. "Eureka！" Li jumped to his feet， cheering for his success in detecting important information.

Li has short hair， a round face， and wears glasses—he looks like a typical science nerd. However， his sturdy physique and suntanned skin distinguish him from a frail scholar. He is a man of both the pen and the sword. At work， he usually sits in front of the computer for the whole day like an unwavering black iron tower. During exercise， he removes his glasses and becomes a human dynamo， prompting an easy association with a soldier charging forward on the battlefield. "Wearing a mustache and taking off his glasses， he looks much more like ‘Zhang Fei'， one of the fierce generals in the Three Kingdoms period in ancient China，" one of his colleagues joked. Li responded with a simple grin， making him all the more like Zhang Fei.

"A strong body is a good asset， as a weak one could hardly stand the strenuous work，" he says with a wide smile on his round face. But once he gets on duty， he immediately turns serious and keeps a poker face.

Counterfeit medical mask scams erupted in early 2020 when the Covid-19 pandemic broke out. The police force of Hechuan District took action to crack a fraud of this kind. The suspect had falsely claimed that he had masks in stock and put them on sale online for 2-4yuan a piece. In a dozen days， he swindled consumers out of over 1 million yuan.

With the suspect arrested， the top priority was to identify the victims. However， the illegal money was so huge that even the suspect could not figure out how many people he had cheated. This tough nut was handed over to Li.

"This is hard-earned money from the victims. They must be anxious. ，" he recalled and threw himself into the lab immediately.

On the workbench were the suspect's three mobile phones. Unfortunately， the suspect had deleted all data from the phones， posing a new challenge for evidence collection and further investigations. Li tried everything for two days and nights， and finally recovered the fraud information from the phones. The transaction history here covered showed a total cash flow of over 13 million yuan， through 17，834 transactions for 3，361 buyers. After scrutinizingthe figures and chat history， he identified over 80 victims across the country， and returned the money to its original owners.

"Data Doesn't Lie"

Li is now deputy chief of the Forensic Science and TechnologyBrigade of the Criminal Police Branch under the Public Security Bureau of Hechuan District， Chongqing.Ranked as a "national young talent" in this field， he is a member of the Electronic Forensic Science and Technology Committee under the Forensic Science Association of China， and one of Chongqing's first batch of city-level instructors in digital forensics.

In 2010， Li joined the police force in Hechuan District after graduating as a bachelor in computer science. In October 2016， the Public Security Bureau of HechuanDistrict established a digital forensic research lab. Since then， he has been working in electronic forensics. Now a "top gun"of the lab.

Unlike criminal police officers， who attend crime scenes personally and use their criminal investigation techniques to collect fingerprints and marks as physical evidence， Li assesses digital evidence. The electronic lab is his battlefield， where he fights against a vast ocean of information.

"An electronic device may know a person better than his or her family. We discover vital clues or crime history from those devices，" he says. He can retrieve data in the lab from a wiped computer， smashed hard disc， acid- or water-soaked chip， or even a broken mobile phone. From that data he gets important information to form a complete chain of evidence.