There's a dead body on a bed and on the floor is a pair of scissors. The scissors were instrumental to his death. Yet there was no trace of blood. The body reveals no sign of any cuts or bruises. How could the person have been murdered with a pair of scissors?
The victim is hooked to an IV in a hospital bed and the murderer cut the tube.
He was deathly afraid of scissors, and merely seeing them caused him to die of heart attack.
The murderer didn't mean to kill him, he was simply cutting out a get well soon card when the sick man woke up.