What does the below image rebus riddle means ?

A person was killed at a house party. When the police arrive, there are six people present in the house who are the friends of the victim. The name of the friends is Rohit, Aman, Nick, Gagan, and Randy.

Near the dead body, they find a few numbers written with blood by the victim on the floor. The numbers are 8, 5, 4, and 11.

The police arrests one of the friends for the murder. Whom did they arrest and why?

Buy me, smell me or deliver me, I do not change.

Who am I?

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

Can it be possible to build a house that has all its four walls facing towards the South?

You need to move three matchsticks to form three squares. Can you do it?

In a mathematical quiz, you are asked the following question:

Use three 9s in a mathematical expression without dividing or multiplying to form the number one.

Can you answer the question?

Find the next number in the sequence

5 12 24 36 ?

Replace the letters of words with a number so that the below equation holds true

BASE +
BALL
---------
GAMES
----------

Prove that twice of ten is the same as twice of eleven.