Serious Crime Unit 1

Chapter 720 Gunshots on a Rainy Night (17)
"The suspect did not leave the scene through normal channels, so the suspect could not be identified from the two monitors on the south and north sides of the scene. He must have left from the roadside of the scene, because our visual investigation team has seen a large number of We have carefully compared the videos and found that none of the vehicles in the surveillance videos have stayed at the scene, even for three seconds - this can be calculated." Lu Yingying answered.

"Yingying, can you really calculate so accurately?" Xiao Ke asked.

"Of course, the monitoring blind spot at the scene is about 150 meters. I have calculated that the speed of all passing vehicles, including motorcycles, is between 40 and 80 kilometers per hour. Then, it only takes about 150 seconds for the car to cover 8 meters. However, after parking the car and then opening the trunk until the person hides in, it will take at least five seconds, so it is impossible for the murderer to escape in this way."

"But we didn't find valuable footprints on both sides of the road at the site." Wu Jiang said.

"It rained on the night of the crime. Even if the murderer left footprints when he escaped, they have been destroyed by the rain. If the murderer wore shoe covers and entered the scene, it would be almost impossible for us to find the footprints. Even if we find the footprints, it is of no value. This It was a well-planned murder."

"Captain Jiang, we originally assumed that the person who called the police was the murderer. If the hypothesis is true, then I think the murderer may be a habitual criminal. If this is the case, his voice may be in the voiceprint database. It is better to enter his voice into the voiceprint to identify it. Let’s try it in the library?” Lu Yingying looked at Jiang Yiming and said.

Voiceprint is the sound wave spectrum carrying speech information displayed by electroacoustic instruments. It is not only specific but also relatively stable.After adulthood, a person's voice can remain relatively stable for a long time.Whether the speaker is deliberately imitating another person's voice and tone, or speaking softly in a whisper, even if the imitation is perfect, the voiceprint will never be the same.Based on these two characteristics of voiceprints, investigators can compare the obtained criminals' voiceprints and the suspect's voiceprints through voiceprint identification technology, quickly identify the criminals, and provide reliable evidence for investigation and solving cases.

"However, our country's voiceprint database is not perfect yet, and its capacity is not large. It is collected from prisoners, police, soldiers, alarm workers, special industry personnel, etc. The probability of successful comparison is very low. Even if the comparison is successful, it cannot Use it as evidence to accuse him of murder." Xiao Ke didn't think it was interesting.

"Yingying is right. If the comparison is successful, at least we know who called the police? Let him tell the situation at that time, and we may find valuable clues from it." Jiang Yiming agreed with Lu Yingying's approach.

Lu Yingying is good at comparing voiceprints. She first inputs what the caller said when calling the police into the computer, and then opens the nationally shared voiceprint database to search. Because it is an automatic search, she makes a cup of tea and waits for the computer results, but , after waiting for more than two hours, there was no beep from the computer, and in the end the comparison was not successful, which made her slightly disappointed.

Jiang Yiming's cell phone rang. Seeing that it was Wang Xiaozhou, he thought he might have found a clue, so he quickly pressed the answer button: "Xiao Wang, why are you free to call me today? It's not easy to be a film police officer. You have to take care of so many people." Many places.”

"Captain Jiang, we have found the motorcycle you are looking for. This man is being held in the police station by us. Please send someone over to have a look. If you haven't come, we don't dare to interrogate him for fear that he will be naughty and confused." our eyes.”

When Jiang Yiming heard this, he was very happy and said that they would go there immediately. After hanging up the phone, he went to the office area to call Zhou Ting and went with him to the Daliang Village Police Station.

When they walked into the Daliang Village Police Station, they saw an unlicensed Qianjiang motorcycle parked under the banyan tree in the yard. Zhou Ting took out the screenshots for comparison. Its newness and shape were exactly the same as the photos. The cover on the handlebar and the protective frame on the front are also the same. It can be confirmed that it is the motorcycle that the caller was driving at the time.

At this time, Wang Xiaozhou walked out of the office. When he saw them on the second floor, he called out: "Captain Jiang, please come up and sit down first. I have made tea and am waiting for you."

"Okay, let's come." Jiang Yiming waved to him.

After they went upstairs, Wang Xiaozhou explained the situation to them: It turned out that Wang Xiaozhou and several auxiliary police officers were patrolling the street, and the motorcycle passed by them. Wang Xiaozhou took a look and felt that the motorcycle was very strange. He looked familiar and had no license plate, so he stopped the motorcycle owner who had already driven more than ten meters away. The owner didn't know what was going on, so he stopped the motorcycle.Wang Xiaozhou stepped forward to observe the motorcycle, and then remembered that it was the motorcycle they were looking for, so he asked the owner to show him the driving license, but it turned out that the number on the driving license was not that motorcycle.The owner of the car was a young man who had been sentenced to half a year in prison for theft. Wang Xiaozhou called him and the car to the police station and detained him in the interrogation room.

Together they went to the interrogation room to interrogate the young man. It turned out that his name was Cheng Xiaochen. He was 19 years old and an unemployed young man. He was sentenced for stealing a motorcycle last year and was released in November 2017 after serving his sentence.After I came out, I spent all day hanging out on the streets, hanging out with some shady people, and had no intention of starting a new life.

"Cheng Xiaochen, where did your motorcycle come from?" Jiang Yiming looked at him and asked.

"Officer, I didn't steal the motorcycle this time, I picked it up." There was a proud smile on his lips.

"Does pie fall from the sky? Then tell me when and where you picked it up?"

“On the afternoon of January 2018, 1, when I passed Lao Du Snack Shop on Mahua Lane, I saw the motorcycle parked next to it. The key was still inserted in the switch and there was no license plate. I immediately felt that the owner of this motorcycle was too careless. , so I kept it in mind.

"I was invited by my friend 'Tiger Head' to have dinner. After dinner, we went to a disco bar to dance. We came out of the disco bar and went to have supper. It wasn't until around 3 a.m. on the 3rd that I took the ride. After returning to Daliang Village, I got off the bus at the entrance of the village. When I passed Lao Du Snack Shop, I found that the motorcycle was still parked there.

"I thought some drunk man must have forgotten the motorcycle, so I walked closer to take a look, and saw that the car key was still in the car. This made me very excited, because I drank a lot at that time and became bolder. , so I turned on the switch and tried to see if it could start. As soon as I pressed the switch, it started.

"I saw that there was no one around, so I got on the motorcycle and rode it home. I thought it was a gift from God, so I rode it around every day, of course, most of the time at night. And we have to avoid the traffic police, but I didn't expect that I would fall into your hands now." He was very unwilling.

"Where were you from 1 to 2 o'clock in the morning on January 0?" Jiang Yiming felt that Cheng Xiaochen was unlikely to be the murderer, because the murderer was a calm and calm person, and his voice did not sound like someone calling the police.Lu Yingying said that the voice of the person who called the police seemed to be between 1 and 25 years old. The voices of each age group will be slightly different. The voices of young and old people can be heard at once. After voiceprint analysis, the age of the speaker can be determined. Frame between 35 and 5 years old.

"It was New Year's Day, and a few brothers and I played all night at Hero Disco." He answered calmly.

Jiang Yiming asked Mi Lai to send Cheng Xiaochen to the detention center. He would first detain Cheng Xiaochen for a week on the grounds that he stole the motorcycle, and then wait for the results of their investigation.Cheng Xiaochen looked very innocent and loudly protested against Jiang Yiming's arbitrary detention of people, and wanted to sue him after speaking out.Jiang Yiming thought his words fell on deaf ears.

Jiang Yiming put on gloves, inserted the key into the keyhole of the suspect motorcycle, started the motor, and drove back to the criminal police team. He hoped to find the fingerprints or biometric materials of the caller from the motorcycle, because this was deliberately done by the caller. The motorcycle was left there for people to steal, in order to destroy evidence or divert their investigation attention.

(End of this chapter)