Everything at the crime scene, even the air, light, sound, smell... is traceable.
Everything at the crime scene, even the air, light, sound, smell... is traceable.
Criminal technology makes them have nowhere to hide.
Criminal technology is an important part of public security work. In the blink of an eye, Zhejiang's criminal technology has never stopped in the battle with criminal crimes.
Last year, Zhejiang police won two firsts in the three major battles of video comparison, fingerprint comparison and DNA comparison of the national public security system.
1
On-site investigation box
From the old man to the treasure box
On-site investigation of criminal cases is a very professional technical job and a hard and tiring physical job.
The older generation of criminal investigation experts often say: "You must squat down and lie down on the on-site investigation", which refers to the working status of the investigators on the scene.
technicians have to carry the survey box to the site with their inspection box. This survey box is like a treasure box, with various tools and "high-end" equipment for extracting on-site physical evidence.
Before, when the surveyor went to the site for investigation, the three old things in the survey box were: a magnifying glass, chemical reagents and a flashlight.
Former political commissar of the Criminal Investigation Detachment of Zhoushan Public Security Bureau, Xu Haibin, has won the honorary titles of "fingerprint expert" of the Ministry of Public Security and "Investigation Expert" in Zhejiang Province. He is an old criminal police officer who has worked for 40 years.
In the 1970s and 1980s, Xu Haibin and his team went out to handle cases "relying on their legs and two wheels", and two wheels were bicycles.
There are many islands in the Zhoushan area, so boats are an important means of transportation for them to handle cases. "The ferry flights were very few at that time, but we had to arrive at the scene in time." Back then, the police would temporarily dispatch fishing boats from the docks, and even borrow gunboats from the troops to the scene. It was also called Zhoushan District Public Security Bureau at that time, and there were several jeeps and and motorcycles, which were only used when major cases were serious.
Back then, the flashlight in Xu Haibin's investigation box was a little more advanced than other police officers. "Generally, police officers are equipped with two batteries, and we need to observe the scene carefully, so ours is a three-battery flashlight, which is a relatively luxurious equipment."
But the light of an ordinary flashlight cannot meet the needs of on-site investigation, "Many traces cannot be revealed under normal light."
In the early 1990s, ultraviolet observation lamps and multi-band light sources appeared, but the power supply of these lighting equipment was electric boxes. At that time, there were no lithium batteries. One electric box weighed fifteen or sixteen kilograms, which was very inconvenient to carry.
Now, there are a wide range of "baby" installed in the survey box: portable infrared night vision instruments, metal detectors, footprint scanners, portable smoke display systems... Various powder display agents, magnifying glasses, compass, rulers, tweezers, sub-gauge standards, multi-use knives, combined rotating tools, glass knives, physical evidence bags... There are also many equipment used for on-site lighting, including survey lamps, waterproof and explosion-proof search lights, multi-band light sources...
This is still the general "standard configuration". The survey box weighs about 20 kilograms. If it is a little more, it will cost nearly 30 kilograms. Often, surveyors carry a box to the scene with their left and right hands.
weight is heavier than before. Fortunately, "there is a convenient transportation now, and cars can be accessed on village roads and rural roads, so it is also very convenient." Han Chongde, an old criminal investigation expert, entered the industry in 1973 and has been inspecting the on-site traces for 45 years.
2
Anatomical room
The new anatomical room invested more than 17 million
on the site. The good partners of the trace examination technicians are: forensics and criminal photography.
Before, the forensic doctor appeared on the scene, carrying a large box of more than 20 kilograms, containing large and small instruments.
At that time, there were no special anatomy rooms in many places. As soon as the murder occurred, the forensic doctor dissected the patient on the spot, and the trace examination technician "did" his partner and helped him hand over the equipment.
Now, there are special anatomical rooms in various places, such as the anatomical rooms of the Criminal Investigation Detachment of Ningbo Municipal Public Security Bureau invested more than 17 million yuan.Pang Hongbing, the captain of the Criminal Technology Brigade of Ningbo Criminal Investigation Detachment, has been working as a forensic doctor for more than 20 years. This is the "third generation" anatomical room built in his hands.
"The earliest anatomical chamber is actually an anatomical table. The second-generation anatomical chamber has a room and a table, but it is not well ventilated." In the "third generation", there are 7 dissection tables and a mobile dissection table. The "lancet" used is "Shuanglien"...
Generally, a municipal-level anatomical chamber has three dissection tables, so why do you need so many dissection tables?
"avoid car crashes". He said that because the anatomy rooms are located in funeral homes, the funeral homes are generally in the suburbs, the criminal investigation brigade in the main urban area also shares the anatomy room with them.
Now, criminal investigation forensic doctors usually do not need to carry a "lancet" with them, and the investigation box is lighter. A box weighing about seven or eight pounds contains physical evidence bags, test tubes, tweezers, steel tape measure, disposable anatomical clothes, gloves...
3
physical evidence bags
Physical evidence bags
Physical evidence bags were used to use plastic bags to hold
physical evidence bags, and they were also "transforming". "In the 1970s, when I first came in, we used paper boxes, paper bags, etc.," Han Chongde said that at that time, as long as it could hold things, it could become a bag of physical evidence. Sometimes, because the physical evidence is a little wet, "the paper bag will seep water and break."
By the 1980s, physical evidence bags became plastic bags, and by the 1990s, there were special physical evidence bags with "sealed vacuum, and some case information could be written on them". The criminal photography technicians at the scene at
are a bit like photographers. Their important equipment is cameras, but unlike photographers, they want to "shoot invisible things." The guy in
has gone from the earliest Seagull, Yasica 120... to now, Canon digital cameras are standard. The photographer who was photographing the photo on the spot, he returned to the unit and went to the "darkroom" to check the photos. Now they can "wait immediately".
In the investigation box they carry, there are also special photography light sources, ultraviolet infrared cameras, multi-functional cameras, cameras, photographers, and portable nonlinear video editors... "Now, with PS technology, mobile darkrooms can't be used, and pictures can be processed on the spot," said Wang Xufeng, a nationally renowned criminal photography technology expert and deputy captain of the Technical Brigade of the Criminal Investigation Detachment of Hangzhou Public Security Bureau.
Nowadays, criminal photography technicians are still video investigators. They have to carry their laptops and hard drives on their backs. Once they arrive at the scene, they will check how many surveillance probes there are around them, adjust the surveillance on the spot, and watch the surveillance...
4
fingerprint
Zhejiang Fingerprint Library There are tens of millions of fingerprint information
fingerprint is our "human ID card". For example, the "Zhejiang No. 1 Unexpected Case" that has been solved for 22 years, one of the key evidence is a fingerprint clue from that year.
fingerprint is one of the "kings of evidence" in the eyes of the criminal police.
Now, Zhejiang police have initially built a huge on-site investigation information system, just like the artificial intelligence AlphaGo who defeated human chess players last year. The latter has tens of trillions of chess scores in his "brain". No matter what move you do, it can immediately start "memory" and come up with a solution.
But before the on-site investigation information system, the so-called "fingerprint comparison" is the technician looking at the cards one by one.
68-year-old Han Chongde, who has been a police officer for 42 years, is a senior engineer of the trace inspection expert of the Criminal Investigation Corps of the Zhejiang Provincial Public Security Department. He has served as a criminal investigation expert of the Provincial Public Security Department for three consecutive terms. He has participated in the investigation of hundreds of major criminal cases in the province and has tested and identified thousands of traces. The major cases that have been involved in the cracking include the Qiandao Lake murder and ship burning case in 1994, the 620 family of six in Fuyang in 2002, the 2002 Yuhang Wang Jun gun case, the "Zhejiang No. 1 Unsolved Case", Ningbo Shaoxing series of robbery and murder cases, and the 2017 Tiantai sweat steam room fire.
According to his recollection, at that time, they made fingerprints into small cards as big as hands, and then integrated the cards into booklets and saved them in the "fingerprint library".
If he wants to compare his fingerprints, he has to run to the "fingerprint library" and look at it one by one, "while looking at the small cards, compare them with the booklets on it."The booklets of
are the "original origins" of today's "fingerprint library".
After years of searching, many of the inks on the "fingerprints" have faded. The difference between fingerprints is between the thin lines, which depends on people's "eyeight", but sometimes, after staring at them for a long time and looking too much, "the whole brain will become dizzy and may miss the key parts."
As a national fingerprint expert, Xu Haibin has also encountered the situation where "it often looks for one or two days without any results."
1996, Zhejiang Province established a fingerprint library and fingerprint recognition system . At present, there are tens of millions of fingerprint information in the fingerprint library established in Zhejiang.
Yao Yuewu, director of the fingerprint office of the Criminal Investigation Corps of the Zhejiang Provincial Public Security Department, said that now, the algorithm of the fingerprint recognition system is becoming more and more refined, and the recognition accuracy of the system is constantly improving, with the recognition rate being above 80%.
5
DNA
In addition to solving cases, it can also help find relatives
1 The reason why we grow up like this rather than that is that DNA plays a role. It is also one of the "kings of evidence" at the crime scene.
1995, the first national DNA database was born in the UK. Four years later, in 1999, Zhejiang police began to carry out DNA identification technology.
Li Youying is the captain of the fifth squadron of the 7th Brigade of the Criminal Investigation Detachment of Hangzhou Public Security Bureau and the chief forensician. With her participation in the establishment, the DNA laboratory of the Hangzhou Criminal Investigation Detachment became the first professional laboratory for judicial identification of DNA in Zhejiang Province.
"A piece of physical evidence extracted on-site may take one week to produce the results, and now it will be fine on the same day." As the efficiency accelerates, many trace traces that were originally considered difficult to identify have been re-adjusted to the scope of easy identification.
DNA technology is becoming more and more advanced, and laboratory equipment is also increasing. Dozens of various instruments of large and small have become the "standard configuration" of DNA laboratories.
In addition to using DNA technology to solve the case, Li Youying also helped Hu Xueyan's grandfather perform an identification.
In 2009, someone unexpectedly found an ancient tomb that had been stolen on the top of Longjing Mountain in Hangzhou. There were two corpses about 150 years old in the tomb, which were suspected to be Hu Xueyan's grandfather and grandmother.
Li Youying was invited to DNA identification of the corpse. "The tomb robbers entered the tomb of the female corpse, so the female corpse was corroded and weathered more severely, and it is basically difficult to identify it." There have been successful cases in
maternal chromosome gene comparison, and she wanted to challenge the Y chromosome gene comparison of the paternal chromosome gene. As a result, the DNA of the Y chromosome of the corpse 150 years ago is consistent with the DNA of the Y chromosome of the paternal descendant of the Hu Xueyan family! The technology
was later mainly used to help the police narrow and lock the scope of criminal suspects when investigating major cases.
DNA has also been used in more fields, such as forensics using it to find relatives.
In April 2016, the Taizhou Wenling Criminal Department cooperated with the civil affairs department to take photos, collect fingerprints, and collect DNA blood samples from more than 100 local "anonymous" rescued by the government.
Forensic Lu Gaosheng was in charge of this matter and suddenly remembered something: "If the files of these rescued people were placed on the WeChat platform, will they help them find their home?"
A post titled "I want to go home, please help me" appeared on the WeChat platform of Wenling Criminal Investigation Department. The post spread very quickly. The day after the post was posted, someone found his sister in WeChat Moments and immediately contacted him. A missing sister for more than ten years went home.
Now, Wenling forensics Qu Zhijun, Lu Gaosheng and his colleagues use DNA and fingerprint databases, plus WeChat communication, to help 36 unknown "anonymous people" go home and reunite.
6
Communication
In the past, the intercom was very clunky now that WeChat communication is much more convenient
1 There is a scene in the movie "Ambushes": Feng Gong played the security department officer to perform the "Ambushes" mission and secretly monitored a red house. Feng Gong guarded the top of the water tower for a full thirty-six days, and was dying when he was discovered. It turned out that the joint defense captain forgot to notify Feng Gong to evacuate in time.
Zhang Chunqiang is the deputy director of the Changxing County Public Security Bureau of Huzhou City and an old criminal policeman. He has experienced such a thing.
At that time, he was still a police officer from the police station. He went to the site with his colleagues. After two days and two nights, they did not dare to move, for fear that the suspect would appear, so he ate bread and drink mineral water. "There was only a BP machine at that time. On the afternoon of the third day, the captain called me BP machine. I went out and called him back. He said that the person was caught and asked me where I was, and then I realized that we had forgotten."
When handling cases, communication was inconvenient, so I sent telegrams and made public phone calls... Xu Haibin remembered that in 1984, the Criminal Investigation Section of Zhoushan Public Security Bureau had a pair of walkie-talkies, but the walkie-talkies were very large and bulky, and the transmission range was limited.
"Now, when handling cases, you can communicate in time with WeChat, and such a story will never happen again," said Zhang Chunqiang.
Solving cases is the mission of every criminal police officer. Those unsolved cases are hidden pain in their hearts.
Those "accumulative cases" that spanned more than ten or even twenty years are the "cold cases" in the eyes of international criminal forensic expert Li Changyu .
He believes that the investigation of a case has a golden period. Generally speaking, in the first three days of the case, the case is a "hot case" and the most easiest stage to solve the case; it becomes a "Warm Case" after three days; if the case is not solved in a month, the case will become a "cold case".
Zhejiang police have launched a special operation to crack down on the backlog of murder cases since last year, re-sorting the "cold cases", re-evaluating, re-surveying, and re-inspecting...
With new criminal technology, Zhejiang police cracked 88 murder cases last year, 3.3 times that of the previous year, and 32 cases have been in more than 20 years.
On December 21, 2018, the DNA Laboratory of Shaoxing Municipal Public Security Bureau just cracked a murder case that occurred in Shangyu 8 years ago and arrested Wang. This is also another murder case that Zhejiang police actively explored new tactics to crack.
On March 18, 2006, Mr. Wang was killed in a shrimp pond shed in Xitangqiao Town, Haiyan County, Jiaxing. Due to limited technology at that time, the case has not been solved for a long time. In October 2017, the police used new technological means to re-examine the original physical evidence extracted on the scene. This murder case 12 years ago finally made breakthrough progress. Ten months later, the task force arrested Shan in Shandong, and then locked in another suspect, Jiang.
1998 On April 20, 1998, a mother and daughter were killed at the second floor home in Jiatian Village, Gaobu Town, Shaoxing County. The young girl was only 6 years old and had a terrible injury. After investigation, the police extracted a blood palm pattern from the scene. On May 4, 2018, Shao Ming, a technical policeman from the Criminal Investigation Detachment of Shaoxing Public Security Bureau, found clues: the traces left on the scene that year were consistent with a man named Wang in Shengzhou .
…
As criminal technology, big data and other technological means become more and more advanced, the truth will eventually come.
