Cheng Shi nodded, and then said to Xiao Wang: "Did you find it in the corner of the bed?!"
Xiao Wang nodded and said: "Not bad!"
Cheng Shi's eyes lit up. If it was in that position, the other party would need to support his body, and then he would leave a mark on the head of the bed!
Alva looked unhappy when he saw his messy bed, but with Albert beside him, he did not explode!
Albert was the first to speak: "Agent Cheng, did you two find any clues just now?!"
Cheng Shi nodded and replied: "We did find the footprints of a suspicious person, maybe someone framed him, although it's not certain yet!
But the identity of Mr. Alva as a major suspect can be ruled out for the time being, and you two can return to the choir in a moment! "
Albert heard this and breathed a sigh of relief, then turned to Alva and said: "Alva, you have to curb your temper in the future. You must have offended that person, and the other person wanted to frame you! "
Cheng Shi looked at Alva who was listening to Albert's sermon and asked, "Yes, Mr. Albert is right. Have you offended anyone recently?!"
Alva said with some embarrassment: "I know I have a bad temper, but I really can't think of who wants to frame me for murder!"
Cheng Shi didn't pay much attention, because even if Alva named his name, it could only be used as a reference and not as a clue!
Cheng Shi then looked at Xiao Wang and said, "Xiao Wang, please send these two back to the choir now, and then tell Agent Feng!
We found a set of suspicious people's footprints in the room, so Mr. Alva is most likely framed!
Of course, he was also asked to take the fingerprints of everyone in the choir. As for Agent Deng and I, we will continue to look for the identity of the fifth person here! "
Xiao Wang nodded repeatedly after hearing this, and finally said: "I understand, I will tell Agent Feng!"
Then Cheng Shi and Albert said, "Please go back first. We have to continue the investigation. As for Mr. Alva, he will no longer be regarded as the only suspect!"
After watching Xiao Wang and the other three leave, Cheng Shi said with a serious face: "Deng Xin, stay here and don't leave. I'll be back in a minute!"
Deng Xin nodded and watched Cheng Shi turn around and leave. After Cheng Shi left Alva's residence, he first went to the hospital!
He revealed his identity as a detective and wanted to ask them for some silver nitrate solution, but there was no silver nitrate solution at the hospital!
Cheng Shi had no choice but to settle for some silver nitrate, then rushed to the patrol room and went directly to the basement to find Francis!
When Francis looked at Cheng who walked into his office, he was the first to say: "Agent Cheng, you came too early, my test results haven't come out yet!"
Cheng Shi placed the silver nitrate particles in front of Francis and said with a smile: "I'm not here to ask about the test results. I just want to trouble you to make these silver nitrate solutions into a solution!"
Francis said a little strangely: "Things like silver nitrate are poisonous. Agent Cheng, what are you going to do with it?!"
Cheng Shi looked at Francis who looked confused, hesitated for a moment, and decided to tell something that had not been discovered in this era!
"Spray silver nitrate solution on wooden objects, and then expose them to sunlight, and fingerprints left over a long period of time will appear on them!"
Francis opened his mouth in surprise and stared at Cheng Shi and said, "What you said is true. Why don't I know this? How did Agent Cheng know?!"
Cheng Shi had no choice but to explain: "Once I went to see a doctor in the hospital, and the nurse accidentally broke a bottle on the wooden table in front of the window!
I saw a black fingerprint appear. Although it soon turned completely black, I paid attention to it!
I then asked the nurse and learned that the thing was a silver nitrate solution. I tested it myself afterwards!
Spray those solutions on those wooden products, and then expose them to sunlight. A clear black fingerprint will appear in a very short time, and then all of them will turn black! "
Francis said with some surprise: "This is a big discovery. I'm going to get you some solution right now!"
Cheng Shi thought for a while and said: "It's best to find a way to get a container that can be sprayed, so that you can make the most of him!"
Francis nodded to show that he understood, and took protective measures for himself before using laboratory utensils to make the silver nitrate solution!
Cheng Shi started waiting outside the laboratory. Ten minutes later, Francis walked out with a bottle!
Francis said excitedly: "I can't wait to experiment now. This is a major discovery in fingerprint testing in the forensic field!"
Francis paused and said, "I wonder, has Agent Cheng told other forensic doctors about this discovery?!"
Cheng Shi continued: "I discovered the effect of silver nitrate by chance, and I haven't told anyone else yet!"
Francis stared at Cheng Shi excitedly and said, "Really, that would be great. If it is as you said, I will start studying the principles of this thing!
If I publish it again, it will definitely cause a sensation. Of course, I will definitely name it as Agent Shangcheng. After all, you are the discoverer of this! "
Cheng Shi said with a smile: "It doesn't matter. I'm going to the scene to check my fingerprints now. Can you lend me another camera?!"
Francis smiled and said: "That's no problem. I'd better go to the scene with you. Fagan can do the testing alone!"
Cheng Shi now asked to go to Francis, so he had no choice but to agree. Then Cheng Shi and Francis came to Alva's residence again!
Deng Xin looked at Francis who came with Cheng Shi, and said with some confusion: "Brother Cheng, why did you find Francis the forensic doctor!"
Cheng Shi replied: "Of course you are here to help us find our fingerprints!"
Cheng Shi then said to Francis: "Mr. Francis, let's start now. I'll spray the solution on the head of the bed first!
Check again to see if there is any problem with the camera. It will be up to you to take pictures after a while, because it does not take long for fingerprints to appear clearly! "
Francis nodded and started to check if there was anything wrong with the camera. Cheng Shi threw Deng Xin a pair of gloves!
Cheng Shi signaled to Deng Xin that he would move the bed to the window where the sunlight came in. Deng Xin quickly put on her gloves and got ready!
After Francis said there was no problem with the camera, the two moved the bed to a position only one meter away from the sun!
When Cheng Shi saw that everyone was ready, he began to carefully spray paint part of the bedside from the left side of the bed!
Cheng Shi saw that the distance was close, and then said: "Francis is ready to take pictures, Deng Xin, put the area where I sprayed it in the sun, and then pull it back!"
Although Deng Xin didn't understand what Cheng Shi was going to do, he still nodded and agreed, and the two of them pushed the head of the bed into the sunlight!
When Cheng Shi saw the black fingerprints appearing, his eyes lit up. Sure enough, he could do it, and he and Deng Xin pulled the bed back!
