A barrister who compulsively viewed child sexual abuse images has argued he "lost himself in pornography" as his life unravelled and was unable to recognise the gravity of what he was doing because of his autism. Richard James Horsley's diagnosis of autism spectrum disorder dominated his sentencing hearing on Monday in the NSW District Court. He has pleaded guilty to possessing more than 1600 child sexual abuse images and 16 videos on three separate devices, as well as accessing such material on his iPhone X. The retired barrister once held an office at Sydney's 8 Wentworth Chambers, but on Monday he sat behind his silk, Phillip Boulten SC, and scribbled notes as Mr Boulten asked a judge to spare his client from prison.