For over twenty-five years, John Sweetman worked as a Detective Garda attached to the Garda Technical Bureau in Garda Headquarters, Phoenix Park. He qualified as a Fingerprint Expert and later as a Security Document and Handwriting Expert and has spent the bulk of his career examining crime scenes and scenes of crime exhibits for the purposes of presenting expert identification testimony in Irish Courts.

As a dedicated member of the Technical Bureau, John was involved in numerous serious crime investigations over the years, up until his retirement from An Garda Siochána in 2023. A keen artist, with an excellent eye for detail, John put his talent to use in the meticulous and exacting field of forensic comparison and individualisation, using the skills he acquired during his service as a valued member of the Garda Technical Bureau.

John lives with his family in North County Dublin. Identity: Murder, Fraud and the Making of a Garda Forensic Expert is his first book.