John 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 other violent criminals. His insights have helped law enforcement agencies solve numerous cases. In addition to his work with the FBI, Douglas is an author and has written several books on criminal psychology, including Mindhunter. His contributions to the field have influenced both real-life investigations and popular culture, inspiring shows like Mindhunter on Netflix.