What happened to the empty cans?

In a humble apartment, two hooligans fought. A woman living in the next room immediately called the police station after hearing the incident, and police officers Ed and Jones quickly rushed to the scene. When they broke into the house, they saw that one of the hooligans had his head broken and was dead. Judging from the wound, he died of blunt force trauma. However, when asked about the suspect Sam, he refused to answer.

I searched for a long time in this room without decent furniture, but I couldn't even find a Coca-Cola bottle. To be as blunt as a murder weapon, there was only an empty pineapple can, which was crushed and thrown on the ground.

"Did you hit him with this jar?" Asked the policeman.

"Joke. Do you believe that this empty jar can kill him? " Sam spread out his hands and said casually. Indeed, it is impossible to kill a living person with such an empty jar.

According to the woman who lives next door, Sam never left the room after the murder, and he didn't throw any murder weapon out of the window. What weapon did he use that day and where did he hide it? The two policemen thought for a moment and nodded knowingly. Jones suddenly twisted Sam's arm behind his back. Ed punched him in the stomach. Due to the sudden attack, Sam was in unbearable pain. He vomited "Cough, Cough, Cough ...".

"What's the matter, Sam, pretending not to know?" Ed pointed out the real murder weapon.

What was the murder weapon?

Answer:

The murder weapon was an iron box with something in it. Sam, whose abdomen was badly damaged, vomited due to severe pain. He spat out undigested pineapples. Sam hit the victim on the head with a canned pineapple, killing him instantly. After that, he immediately opened the can and wolfed down all the pineapples inside, turning it into an empty can.