Solution:

It is quite possible. The poison was not on the drink but in the middle of ice cubes. The first one drank immediately and thus the poison could not reach his body while when the other drank after half an hour, the ice cubes had melted. Thus he died.

Solution:

Bob was in China in 2012 & he killed Anderson.

Anderson died of suffocation=>This information should lead you to statement #3 next. From here you should gather that Bob killed Anderson.
Thus leading to statement #4, Bob was in China in 2012.

Solution:

1)The first bit is easy, as the first letter of each plate spells WHODUNNIT IX(A challenge to our Detective.)
2)The second bit is a little trickier, but I gave you the solution.If you read the last three letters in each plate from the bottom up and right to left you get ADVANCE EACH LETTER BY THE NUMBER SHOWN, so advance W by 5 to get B, H by 13 to get U and so on until you spell BUTLER DID IT.

Solution:

She was hoping that the guy would appear at the funeral again.

Solution:

When you mix bleach and ammonia [found in most cleaning products] it creates a deadly gas that can kill.

Solution:

Mark Benson '?' = question MARK, so the note on the door reads 'Question Mark Crimson broke your window.'

Solution:

The forest in which the body is found was on fire. Thus a fire fighting plane was appointed on the task of putting off the fire. The plane went to the nearest lake and scooped up the water to put on the fire. Accidentally while scooping up the water, they also picked up the man swimming in the lake. Unfortunately they did not know the fact and dropped him on the fir along with the water. He died on the spot.

Solution:

The blood came from a mosquito. It bit and sucked my blood last night. It then flew and sat on the ceiling. Determined to kill it I swatted it right there and the minuscule splatter came from it only.

Solution:

This is because Adam is a hangman by profession. Apparently, his wife has been sentenced to death and he had to do it with his own hands.

Solution:

Frost forms on the inside of the window, not the outside. So shweta could not have wiped it off to discover Mr.Ankit's body.