"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."