Rape

"When Li Hui was dazed, the killer sneaked into the living room. However, they didn't expect Li Hui to be so physically imposing when he was injured. They got into a huge fight and Li Hui was beaten several times on his head before he eventually collapsed. The killer sliced the victim's throat multiple times to ensure he was dead.

"After that, the killer cleaned up their traces. They closed the curtains and switched the power switch back on. The power box was at a blind spot, so they didn't realize they had left behind a bloody print. That would solve all the questions about this case."

"Very good. But why did the killer choose to close the power switch beforehand?" Mo Li asked Qin Xuan.

"Because they knew they weren't physically stronger than Li Hui and thus required the element of surprise?" Qin Xuan thought and said.