In the investigation of Stavroula Leventaki's murder, forensic experts utilized a specialized tool known as Blue Star. This chemical reagent is deployed when perpetrators attempt to erase evidence by cleaning floors or disabling security cameras. Even after thorough cleaning, Blue Star can detect trace amounts of blood that are invisible to the naked eye. By reacting with hemoglobin, the substance glows under specific lighting conditions. This process allows investigators to reconstruct the crime scene and locate hidden biological evidence. In this specific case, the technology proved pivotal in uncovering the killer's identity. The forensic breakthrough overcame the suspects' efforts to conceal the crime.