A famous chemist was murdered in his own lab.
There was no evidence of any crime except for a piece of paper with the names of 5 chemical substances on it:
On the day he was murdered, the chemist had only 3 visitors: his wife Mary, his nephew Nicolas, and his friend Johnathan. Who did the police arrest?
The piece of paper had a clue on it. If you combine the abbreviations of the chemical substances on the paper, you’ll get the name of the killer: Ni-C-O-La-S.