Gerald Roche Lynch OBE FRIC DPH (1889–1957) was a British forensic scientist and public health analyst associated with several infamous murders as a medico-legal expert. An expert on poisons he appeared as an expert witness in multiple murder cases in the 20th century.
He was an important contributor to the "Bastardy (Blood Tests) Bill" of 1939, concluding that blood tests could accurately prove paternity (the accuracy was much less than modern DNA testing).[1]