Gamble stated that he believed his background as an RUC Special Branch officer may have been a factor in why he was not selected for the role and that his RUC background may have been "unhelpful and perhaps unhealthy for the service".[4][6]
Gamble was a co-author on the UK's first Domestic Homicide Review (Pemberton) and in 2010 was appointed by the then Home Secretary to lead the initial scoping review of the investigation into the disappearance of Madeleine McCann.[9]
Gamble resigned as CEO of CEOP in October 2010.[10] He then created the 'INEQE Safeguarding Group'.
Gamble has been called to give evidence at the Independent Inquiry into Child Sex Abuse (IICSA) on two occasions. The first related to child abuse on the internet, and the second to faith-based institutions.[11]