Han Bin asked the property company for a list of owners and contact information of Building No. 6, which he would use when checking and monitoring.

As for the delivery lockers in Building 6, there is a gap above each locker, which is specially used to deliver letters, leaving DNA and fingerprints very unlikely, and even if there is, it is not necessarily the murderer's.

After Li Qin and Bao Xing copied the surveillance, the scene was basically surveyed, and Han Bin led people back to the Yuhua Branch.

After Han Bin returned to the office, he found that Li Hui had returned from the Huaguang Police Station, "You kid is fast." ”

Li Hui said, "After handing over to the comrades at the police station, I will come back." ”

Han Bin yawned and sat down in his chair, "What clues do they have over there?"

After receiving Song Jingshan's alarm, they made a special trip to the community where Song Jingshan lived, and also copied the community's surveillance video. Li Hui put a document in front of Han Bin, "This is the file at that time, with Song Jingshan's records and their investigation. ”

Han Bin looked through the file, and Song Jingshan's transcript was roughly the same as today's transcript.

However, there was a record that caught Han Bin's attention, according to Song Jingshan's confession, he found more letters in the express cabinet on the morning of June 10, and the last time he checked the express cabinet was on the morning of June 8, which means that the last time he committed the crime was between June 8 and June 10.

Before making a record, Han Bin also asked about the situation of the first threatening letter, and also asked him about the precise time, but Song Jingshan only remembered that it was the police who reported on June 10, and he couldn't remember the time he found the threatening letter when he checked the express locker last time.

Apart from this, there are no other valuable clues on the dossier, and the process of investigation is simple.

Han Bin threw the file on the table and glanced at the crowd, "Don't say anything, check the surveillance." ”

"Not only should we check the surveillance of the last five days, but also the surveillance on June 8, June 9, and June 10, and we must compare the surveillance video of the first threatening letter with the second threatening letter to find out the common characteristics of the suspects. ”

"Yes. The crowd split up.

Not long after, Du Qi also returned from the communication company, and he was responsible for investigating the call records of 'Brother Zhao' to see if he could find clues about Brother Zhao from his contacts.

After Du Qi reported to Han Bin, Han Bin asked him to take Mai Jun to check together.

It's also a tedious job.

Han Bin poured a cup of tea and stood by the window thinking about the case.

This threatening letter seems a little abrupt, but if you think about it carefully, you will find that the timeline of the threatening letter is likely to be before Song Bochen's death.

Song Jingshan was on a business trip on September 6, which means that on the 6th, 7th, 8th, and 9th, the suspect may have delivered threatening letters, and Song Bochen died on the afternoon of September 9.

It is likely that the murderer first sent a threatening letter, and then killed Song Jingshan's son Song Bochen out of revenge.

Song Bochen's death also happened to be the sentence of the broken family.

But if the killer has decided to kill, what's the point of him sending a threatening letter?

Could it be that it is to remind Song Jingshan? This is a bit unreasonable.

Of course, there is also a possibility that the murderer sent a threatening letter after killing someone, the purpose of which was to stimulate Song Jingshan.

If that's the case, the grudge between those two people is great.

It stands to reason that there is really such an undying contradiction between the two sides, and Song Jingshan should know about it, but Han Bin asked again and again, but Song Jingshan said that he did not have a grudge against anyone.

Han Bin picked up the cup and drank tea, but found that the tea in the cup had bottomed out.

Han Bin poured another cup of tea.

Han Bin also has a guess whether this will be the murderer's trick.

The murderer's target was Song Bochen, and he also had a feud with Song Bochen, but in order to divert the attention of the police, he sent a threatening letter to Song Jingshan, the purpose was to let the police track down the situation around Song Jingshan, thus ignoring the clues around Song Bochen.

If this is the case, it means that the murderer began planning three months ago, or even earlier......

At noon, Han Bin was eating in the cafeteria, and during the meal, he exchanged the case with Zeng Ping, they were still tracking two fake cars, and the general direction and location had been locked, but it would take some time to find the suspect vehicle.

After the meal, Han Bin took a lunch break as usual.

At two o'clock in the afternoon, I washed my face and refreshed myself.

There has been no progress in monitoring, and Han Bin is somewhat dissatisfied with their efficiency, and in the afternoon he is ready to devote himself to the work of verification and monitoring.

"Knock knock......" There was a knock on the door outside the office.

"Come in. ”

Lu Wen pushed the door and walked in, and said with emotion, "Team Han, every time I see you in the office, I have a feeling of being like a dream." ”

Han Bin shook his head and smiled, "Did you find anything?"

"I don't dare to come to your door without a clue. Lu Wen handed over a document, "We have checked the two envelopes, and only one person's fingerprints were found on the second threatening letter, which were compared with Song Jingshan's fingerprints." ”

"The fingerprints of four people were found on the first threatening letter, one was Song Jingshan's, one was Song Bohui's, and two fingerprints were found. ”

Han Bin touched his chin, he had asked Song Jingshan before, according to Song Jingshan, when he found the first threatening letter, he found Song Bohui and his daughter Song Boxia, that is to say, in addition to Song Jingshan, Song Bohui and Song Boxia have both read this threatening letter.

The fingerprints of Song Jingshan and Song Bohui were compared, and Song Jingshan's words were also confirmed on the side, but I don't know if there are Song Boxia's fingerprints in the remaining two fingerprints.

Han Bin briefly told Lu Wen about the situation and asked him to go back and wait for news, Han Bin had to determine whether there were Song Boxia's fingerprints in these two fingerprints, and if so, they could be ruled out for the time being.

In this way, when comparing the database, the workload will be reduced by half, which can be regarded as for the sake of the technical team.

After Lu Wen left, Han Bin slapped his face and said to everyone, "You should have heard what you said just now." The technical section found suspicious fingerprints on the first threatening letter, most likely left by the suspect, as long as you find a suspicious person from the surveillance, you can compare the fingerprints. Let's work harder. ”

The crowd responded twice.

Han Bin didn't care about them anymore, and called Song Jingshan and asked him to inform his daughter Song Boxia to come to the Yuhua Branch.

However, Song Boxia didn't wait, but Han Bin waited for another guest.

"Jingle bell......" Han Bin's mobile phone rang.

"Who?"

"Is it Captain Han?"

"It's me, who are you?"

"Are you going to investigate the case of the threatening letter?"

"Yes. Han Bin was a little puzzled.

"I have some situations that I would like to relate to you. ”

"What's the situation?"

The person on the other end of the phone was a little hesitant, "I...... I can tell you face to face, I can't say a word or two about this matter. ”

"Yes, where are you?"

"I'm at the door of the Yuhua Branch. ”

Han Bin walked to the window and saw a man standing next to the guard's room, "You go into the courtyard, I'll have someone pick you up." ”

"Good. ”

Hanging up the phone, Han Bin greeted Zhao Ming and asked him to go downstairs to answer the man who called.

After a while, Zhao Ming led a middle-aged man in, wearing a gray T-shirt, with his head down, looking a little cramped.

"Please take a seat, what do you call it?" Han Bin asked.

"My surname is Hong, and my name is Hong Jianying. ”

"I think you're a little familiar, haven't we seen each other somewhere?"

"Yes, I work at the property of Rhodium Garden Community. ”

"I remember, I've seen your photos at the property, and you're in charge of cleaning Building 6. ”

Tian Li handed over a glass of water, and Hong Jianying caught the cup with both hands, "Yes, you have a good memory." ”

The other party is a cleaner in Building No. 6, and it is likely that he has seen the person who delivered the threatening letter, Han Bin subconsciously asked, "Do you have any clues about the suspect who submitted the threatening letter?"

"I'm ......" Hong Jianying swallowed and took a deep breath, "The letter is...... I voted!"