معماهای جنایی Crime riddles به انگلیسی

A serial killer kidnapped people and made them take 1 of 2 pills: one was harmless, and the other was poisonous. Whichever pill a victim took, the serial killer took the other one. The victim took their pill with water and died. The killer survived.
How did the killer always get the harmless pill?


Once on a winter day, John found his friend dead in his own house. John called the police and said that he was just passing by Jack's house and decided to come in.
He'd been knocking and ringing the bell for a long time, but all he got was silence. However, he could see the light in the room through a frozen window. He breathed on the iced window glass and saw Jack on the floor.
The police arrested John as the main suspect. Why?


A lonely old man lived in his house in the suburb of a city. He never left the house for long. It was a midsummer Friday when the mailman walked by and called out for the man. There was no answer. The mailman looked into the window and saw him in a pool of blood. When the policeman arrived, he found Tuesday's newspaper, 2 bottles of warm milk, and 1 bottle of cold milk.
The next day, the killer was arrested. How did the police find out who it was so quickly?