When my autistic little brother irritated me, I punched him in the arm. Perhaps he stared at me over the dinner table for one minute longer than is sociably acceptable, or he was throwing a wobbly because he’d overspent his allocated TV time limit, or because asking me the same question 57 times over was 56 times too many.

I feel guilty now for these trivial childhood spats. I thought, in my sinister pre-teen wisdom, that if he knows his abnormal behaviour earns him a punch, he will stop. It was negative reinforcement; a deterrent; some Pavlov conditioning.

It didn’t work.

The autistic do not respond well to deterrents, and this is why Michael Sandford, the 20-year-old British man with a severe form of Asperger’s syndrome, who reached out for a police officer’s gun at a Donald Trump rally, should never have spent a single day in prison.

Clearly no two people on the autistic spectrum are the same, but methods of treatment recommended by the National Autistic Society include empathy, positive reinforcement, cognitive therapy, teaching through comic strips and counselling. Custody, strangely, is not on the list.

Michael told officers he planned to assassinate the presidential candidate. It has since been diagnosed as a psychotic episode. He has been in jail since 18 June and will be home, good behaviour permitting, in another four months.

Custody has been “torture”. When in isolation, his mum Lynne Sandford says he is locked up 24 hours a day and seven days a week, is stripped of clothes, deprived of toilet paper in case it is rammed down his throat as a suicide method, and with little explanation, is not allowed books.

Lynne believes his punishment should be firm for what was deemed a serious security scare, but if sentenced in the UK, I’ve no doubt this punishment would have recommended a hospital order or counselling.

He’s had death threats too. Michael takes life literally. And, by the way, he has anxiety and severe obsessive compulsive disorder.

If I, in jest, told my brother someone was going to kill him, he would repeatedly ask me for clarification until I retracted. If he was placed in isolation without given explanation well in advance, his stress would be incalculable. He is so vulnerable, and so gullible, he’d be at the mercy of inmates.

It’s all too easy to empathise with Michael and Lynne’s situation. He is from the same town as us. His mum and mine made friends via the National Autistic Society. They've both devoted the best part of their lives to their kids. Mum has fought unconditionally for the best education possible for my brother. But now he’s 22, and in a Government-paid supported living house with other disabled young adults, she frets that she’s not doing more. But Michael’s trauma has given some perspective – at least my brother is safe at home in the UK, where he would never face such draconian incarceration measures.