Murder Mystery: Not a case of suicide?

Question

A detective is called upon a crime scene. He finds that a body is lying on the ground in front of a multistory building. By all the means, it looks like a simple suicide case. But there are doubts in his mind.

He goes to the first floor and moves into the room facing the direction of the body. He opens the window in that direction and looks down towards his team. The he goes to the second floor and again moves into the room facing that direction, opens the window and looks down at his team.

He continues with the same process till the top floor. After that, he returns back to where his team is standing. He tells them that it is not a suicide case.

How did he come to such a conclusion?

Answer 1

At every floor, the detective had to open the window himself. If the man had committed suicide, then at least one of the windows must have been open. A person who is committing suicide won’t close the window behind him. Thus he knows that someone pushed him off the edge and closed the window afterwards.

Answer 2

At every floor detective opened the window. In case of suicide one window would have been open

Comments

Suppose if the man was jumped from top of building. Can it be judged only with the window?