Craig Semple was a career detective in the New South Wales Police Force for twenty-five years, investigating homicides, outlaw motorcycle gangs and hundreds of other serious crimes. Medically retired from law enforcement in 2013 due to psychological injuries, Craig is now a sought-after keynote speaker and mental health advocate.

Craig is the founding director of Mentality Plus, through which he has developed and delivered mental health, wellbeing and resilience education to thousands of people all over Australia. He is also an ambassador for the Black Dog Institute. Craig's first book, The Cop Who Fell to Earth, was published by Echo Publishing in 2023.