For suspected autistic spectrum disorder (hfa) in a 3 yr, which professional is better to see for evaluation - psychiatrist, psychologist or therapist?

Either psych: Any of the three may be able to help. In order psychologist, psychiatrist, less likely, a therapist.

Could see: A developmental specialist (pediatrics or psychologist) or a child psychiatrist.

Child Psychologist: One that clearly states a specialty in this area. One who can do necessary neuropsychological testing and has professional connections to neurologists too. Check online for National Organizations for referrals close to you. Our roots are in evaluation! Hope it goes well!