John E. Douglas is a former FBI agent known for his work in criminal profiling. He played a significant role in developing techniques to understand the minds of serial killers and violent offenders. His insights have helped law enforcement agencies solve complex cases. Douglas is also an author and has written several books, including Mindhunter, which details his experiences and methods in criminal psychology. His work has influenced both real-life investigations and popular culture, inspiring the Netflix series Mindhunter, which dramatizes his early career in the FBI's Behavioral Science Unit.