Can you legally skip the weeks of intervention when testing a child for special

[EzzyLa]

education? When a child is obviously mentally impaired or autistic do you still have to try interventions in the classroom and prove that they do not help the child? The whole process of identifying a child with special needs can take 7 months after the weeks of interventions and the window allowed for testing. Children end up losing most of the academic year. Our district has a high transient rate so some children must start the process all over again when they go to a new school.
I was told that we needed to document six weeks of interventions becuase federal mandated it. The last child I worked with was not tested until April after the teacher noticed problems in August. The mom was in denial about any problems and nearly cried when school testing and a medical visit showed that she was M.R. of course later we find out that the mom would cry because she did not know why her daughter could not learn her numbers or letters. My current student right now came from a private school that has refused to send us any academic reports. The one time some one answered the phone we were told he was academically low and that they did not believe in special education. I'm going to have to retain him and was told it would not be until next school year that he gets tested if does not make progress a the begining of the year. I was told that him learning 20 letters and how to count to seven is showing progress for first grade.
...and he just now the order of the numbers and letters he can not recognize them if he is just show the number or letter randomly. He has been my student for two months.