The Reid technique is a way that police officers and other investigators talk to people who might have information about a crime to try to get them to tell the truth.
Imagine you and your friends are playing outside and someone breaks a window by accident. Your mom asks you what happened and you know who did it, but you are scared to tell because you don't want your friend to get in trouble.
An investigator using the Reid technique might talk to you and try to be very friendly and make you feel comfortable. They might ask you questions like "Did you see anything interesting or unusual happen outside just now?" and "Do you know anything that might help us find out who broke the window?"
If you say you don't know anything, they might ask you again in a different way or remind you that it's important to tell the truth so they can help everyone be safe. They might also point out evidence (like a soccer ball near the broken window) to show you what they know and try to get you to remember more details.
Overall, the Reid technique is a method that investigators use to get people to talk about what they know without making them feel scared or forced. It's important to always tell the truth and be honest with the police so they can help keep everyone safe.