 How can nuclear science help criminal investigations? Well, atoms don't lie. Criminals may try to cover, clean or conceal evidence, but traces of it will always be left behind. The science of studying atoms is gaining ground in the world of forensics. X-rays, neutrons and ions offer advantages over conventional methods. They can analyse one particle among millions. And pinpoint origin with great accuracy, while leaving crucial evidence intact. How? Ion beams interact with atoms to show the composition of material. With this method, a tiny shot of glass can be traced back to its source. Neutron activation details with precision the amounts of isotopes in a sample, helping to match fragments of a bullet to a manufacturer. Nuclear techniques help to solve crimes, detect fraud and spot forgeries. The IAEA supports research and helps countries in applying these techniques.