Final answer:
The experts in the context of the question indicated that the killer of Marilyn would carry 'traces of blood' due to the violent nature of the crime. This is tied to forensic science, where blood stains can be crucial evidence. This implies that the crime resulted in significant bleeding, marking the perpetrator.
Step-by-step explanation:
The experts stated that whoever killed Marilyn would have traces of blood on them because of the nature of the crime. When analyzing a crime scene, it is often considered that the perpetrator may carry evidence with them, such as blood stains, which can be crucial for investigations. This assertion could be influenced by the context in detective fiction or real-life forensic science where contact with a victim can leave physical evidence on the perpetrator. While this scenario is fictional, it suggests that the nature of the crime was violent and resulted in substantial bleeding, implicating that the killer would unavoidably be marked with the victim's blood.