I hope you like murder mystery like I do, for you will need it for this riddle : The inspector crouched at the victim to get a closer look. It was lying in a ... of it's own blood. What was the victim in?

At the start, I am clean, no history to be seen. Made a mistake? Don't make a scene, man. To start with a fresh me, just wipe me clean again.

Comparable to a winter tree, I hold many layers, Yet I never feel cold. I keep secrets without speaking, Guard identities without judging, And reveal truths only when opened. Fear stepping into me, Others are told to come out. In every home I quietly stand. What am I?

In the realm of the mighty door's face, A turning power takes its place. With every twist, A world you resist, Unlocking secrets in its embrace.

I look like a triangle But, I have four corners. What could I be?