Almost half of Victorian male inmates have a brain injury. For Michael, diagnosis was the first step to a new life

‘What I know now, if I knew it back then, I’d be a completely different person,’ says Mike Mayne, who was diagnosed with acquired brain injury at the age of 47. Photograph: Christopher Hopkins/The Guardian

Michael Mayne does not know precisely when he acquired a brain injury. It may have been in one of two serious motorcycle accidents, or – as he suspects – the consequence of decades of drug use, or a combination of all three. But he knows when it was diagnosed: he was 47 and he had just come out of prison – and not for the first time.

An estimated 2% of Australians have an acquired brain injury (ABI). The most common causes are accidents, trauma, stroke, and foetal alcohol spectrum disorder. But among the prison population, the prevalence of ABI is astronomically high, leading legal experts to argue that the system that is supposed to be providing justice is effectively criminalising disability instead.