Urgent need for CF reasoning questions

One night, a woman writer was found dead in her house. Judging from the scene, it seems that the deceased was writing on the desk before she died, and she was killed by a blow to the head. There is an emergency light on the desk, and the desk lamp is off.

* * Ask the property manager if the power has been cut off. The administrator said, "The power went out for about an hour at about 9 o'clock last night. I think she may have been killed while writing with an emergency light. She turns off the lights very late every day. "

* * asked again: "Who appeared before and after the power outage? The administrator replied: "The boyfriend of the deceased came before the power outage and left the building in a hurry after the power outage. I think he must be the murderer. "

"Are there any suspicious people coming in and out after the power failure?" * * asked again. The administrator thought for a moment and said, "After the phone call, a strange man of about 30 years old came down from the floor where the deceased lived, but I don't know if he had ever entered the deceased's room." * * I heard that we already know who the murderer is.

Excuse me, who is the murderer? What is the basis?

Answer: The murderer is an administrator. The most obvious lie is, "after the phone call, a strange man of about 30 years old came down from the floor where the deceased lived, but I don't know if he had ever entered the deceased's room."

From the words "I have been downstairs", it can be seen that the administrator saw the strange man go upstairs below the floor where the deceased was located. How did he know this man was on the victim's floor?

The second doubt, the desk lamp, if the deceased died during the power outage, why is the desk lamp off? The killer turned off the lamp and left. Unreasonable. I think the deceased died before the power failure, or even during the day (there is no need to turn on the light during the day). When there is a power outage at night, some people put on emergency lights to create an illusion (alive before the power outage), and those who know about the power outage are also administrators.

If it is not enough, ask me again, or ask questions.