People with Autism Spectrum Disorder are more likely to be targeted by the authorities because their behaviour can be wrongly interpreted as being aggressive, says a disability advocate and consultant.

A young woman fatally shot by police in Sydney after she was seen waving a kitchen knife on Tuesday morning had Asperger's Syndrome.

But the former head of Autism Victoria, Murray Dawson-Smith, said the 22-year-old may not have been intending to threaten violence.

He said people with Asperger's Syndrome could become easily agitated when overwhelmed by noises and other sensory stimulants – and that agitation could by others interpreted as aggression.

Mr Dawson-Smith said there had been a number of cases where people on the autism spectrum have accidentally got into a confrontation with Protection Services Officers patrolling public transport.