In 2011, the Howard League for Penal Reform published the final report of the independent inquiry into former armed service personnel in prison.
From the report:
"At the present time the most accurate figure would seem to be the product of a joint quantitative study carried out by the Ministry of Defence and the Ministry of Justice. This asserts that approximately 2,820, or some 3.5 per cent of all those currently in custody in England and Wales, had served in the Forces.
"The study estimated that 77 per cent of ex-servicemen in prison served in the Army, 15 per cent in the Royal Navy and 8 per cent in the Royal Air Force. Furthermore, it estimated that 51 per cent of ex-servicemen in prison are over the age of 45 years and 29 per cent are over the age of 55, which compares to 9 per cent of the general prison population being aged 50 years or over. These statistics suggest that many ex-servicemen in prison have offended a considerable time after their date of discharge.
"Whatever the exact figures for ex-servicemen in prison, it is important to stress that all estimates indicate that ex-servicemen constitute a significant subset."
From the press release:
“While the numbers of ex-servicemen in prison appear stable, evidence from statistical surveys in both England and Wales and the United States show that ex-servicemen are more likely to be serving sentences for violent and sexual offences than the general prison population."