ON a Sunday afternoon, an old woman was killed in her house.

Detective Jerry was called to the scene the next day. He checked everything carefully and asked many questions. He learned that the old woman was very rich. After her death, her nephew could get all her money. But the young man looked honest and kind-hearted.

Jerry questioned him, "Where were you at three on Sunday afternoon?"

"When the murder happened, I was not in my aunt's house," said the man as he took out a photo from his pocket. "I was traveling in . I just got back today. A girl took this photo of me."

In the photo, the young man was standing by a tree stump . The tree stump has many growth rings .

"The photo was taken in Kenya in on Sunday," added the man.

But Jerry said, "No, you are lying. This photo proves that you were not in Africa.."

Hearing this, the young man turned white and admitted he had killed his aunt.

How did Jerry find out that the man was not in that day?
It may have been the type of tree. Certain trees only grow in certain parts of the world. In the UK, we have oak, sycamore, willow, fir, etc but do not have sequoia, baobob, etc. Perhaps Jerry recognised that the tree was native to the country the story is based in, and that it does not grow in Africa.

A second possibility is that the photo has a sign in it saying 'Yosemite National Park' or something similar, which would prove that the young man was local to his aunt on the day.

A third possibility would be if the time/date stamp on the photo was wrong.

I think I've covered a few possibilities.