The increasing misuse of opioids in Europe is an alarming trend, leading to severe social and health consequences. Heroin, a highly potent and addictive opioid, remains the main contributor to the health burden associated with opioid use in the region. Illicit drug characterization and profiling offer valuable insights into the complexity of heroin seizures, assisting law enforcement agencies and forensic experts in gathering evidence for legal proceedings. This study provides a comprehensive overview of the composition of heroin seizures and assesses the feasibility of an electrochemical fingerprint approach for the detection of heroin and its associated components. In the initial phase, the primary focus was on developing an electrochemical sensor optimized for heroin detection. The sensor’s performance was validated using street samples provided by Sciensano, a Belgian health institute, ensuring its accuracy and reliability in identifying heroin. Once the capabilities of the sensor were demonstrated, the discrimination of alkaloids and cutting agents in seized samples was integrated into a customized software script. Subsequently, an extensive validation process was conducted using a new dataset of heroin seizures from the Belgian National Institute for Criminalistics and Criminology. The follow-up verification confirmed the sensor’s effectiveness in detecting heroin, cutting agents, and alkaloids, highlighting its potential as a valuable tool for drug profiling. This portable, user-friendly device with automatic readout could become essential for forensic experts, law enforcement, and harm reduction efforts in addressing the opioid crisis.