"I don't think that's likely." Mo Li said. Xiao Rui probably hadn't frequented this kind of oxygen bar before. "This kind of tank is one-time use only. You have to finish the tank once you break the seal." Mo Li shook her head. "So I find it more likely that someone has repainted the surface of the tank instead of swapping out the content inside."
"Si Lin, get some officers over to the office to check the gas tanks. Tell them to report back immediately if they find something!"
"Yes, sir!" Si Lin immediately took out her phone.
"Then the biggest suspect has to be the secretary! It's her job to prepare the oxygen tanks after all!" Kang Zhi proposed.
"No, Yu Xuan doesn't have the time. The eyes were cut after death. Dong Yun died after 9 pm and Yu Xuan was in a meeting."
Xiao Rui took another mouthful of rice. "Regardless, the culprit has to be able to access the office freely to tamper with the tanks and there are only 3 such people."
"But all 3 of them have alibi..." Kang Zhi sighed helplessly. He really didn't like to talk about work when he was eating.
"Boss, Captain Yu just sent some pictures over." Si Lin's phone rang and she answered it. "They confirmed that Miss Mo Li is right. Two of tanks have been tampered with, they have already sent them for analysis."
Seeing that everyone was almost done eating, Kang Zhi hurriedly stood up to pack the lunch boxes. Si Lin moved to the computer to pull up the surveillance footage.
"Si Lin, give us a report on the footage from yesterday."
"Okay, this is the footage from last night. This is Zhao Hongwei at the underground parking lot from 9 pm to 10 pm; Andy arrived at the business centre at 8 pm and he was at the counters testing out clothes and make-up; At the same time, Yu Xuan was in a meeting, the footage can verify their alibi.
"The only paths that lead to the chairman's office are the elevator and the fire safety escape. The fire escape has been abandoned and it shows no sign of usage. No one used the elevator during the victim's time of death either.
"This is the footage from this morning. The driver Ol' Zhao arrived at 10.10 am and found the body; at the time, Xu Yuan was in a meeting and Andy was testing the colors of lipsticks at the mall."
"So the only movement we don't know is the chairman's?" Xiao Rui sighed. He should know that there wouldn't be any camera inside the boss' office.
When Si Lin took her seat, Kang Zhi clapped, "That's some impressive findings! Sister Si Lin is someone I need to learn from!"
Si Lin rolled her eyes.
Xiao Rui looked at the info Si Lin wrote on the whiteboard. "The victim died between 9 pm to 9.30 pm and he was discovered at 10.10 am. The killer has plenty of time to do all the sick things and escape. But how did the killer get into the office to kill the victim? Why didn't the killer show up on any of the surveillance footage?"
Mo Li picked up a pen and walked to the whiteboard. "There are 3 possibilities to this question. One, the killer went upstairs with someone who can assess the elevator, so the killer might be someone other than our current 3 suspects. Since our 3 suspects have alibi, the killer might have come with the chairman. However, according to Qu Xuan, Dong Xun was still at the office when she left for her meeting and he had no guest."
Kang Zhi nodded.
"The second possibility is that the killer used Dong Yun's eyes to pass the corneal scan, however, Dong Yun's eyes were cut out after his death and not before."
"What about the third?" Kang Zhi realized he liked to listen to Mo Li because he could always learn something.
"The third is a hypothesis of mine but there are some contradictions that need to be ironed out. For example, when did Mr. Zhao said he got the call from the victim?"
"Around 8 o'clock. Do you think we should bring him in for further questioning?"
"Yes, I have some questions for him." Right then Kang Zhi's phone rang. It was a video call from Captain Yu.
"It's like this. We have a man here called Zhao Hongwei who said he has something to report to you, Captain Xiao."
"Well, this sure is a happy coincidence." Xiao Rui said
"What happened to you?" Mo Li couldn't help but ask when she saw Zhao Hongwei.. The man was severely beaten up.