Once upon a time, there was a detective named Detective Deducto. He was the best detective in all the land, known for his use of the Exchange Principle and his expertise in forensic science.
One day, a thief stole a car and Detective Deducto was on the case. He used the vehicle identification number to track down the thief and found trace evidence at the scene of the crime. He then used that trace evidence to create a DNA profile of the thief and eventually, through his powers of deduction, he was able to catch the thief and return the stolen car to its rightful owner.
The end.

Reflections

1. What is the Exchange Principle?
2. How did Detective Deducto use trace evidence to catch the thief?
3. Why was the vehicle identification number important in solving the case?
4. Can you explain what DNA profile means?
5. How does forensic science help detectives solve crimes?