Kidnap victim. Bound hands of a kidnap victim in the boot of a van. The kidnapper's feet are at upper right. Forensic science may be able to help convict the kidnapper through evidence linking the criminal to the crime scene. This may include blood under the victim's fingernails, deposited during a struggle with the kidnapper. Hair, other organic material and rope and clothing fibres can cross-contaminate the body, the car, the cloth and the kidnapper's clothes. Even earth from the ground may adhere to the shoes and help to place the kidnapper at the crime scene.