Your pre-school child has “behavior issues.” Is special education the right place for an aggressive child? Is medication the right remedy? You may never know until you have an evaluation by a competent pediatric neurologist or child psychologist experienced in aggressive behaviors. First, request one from the school district where you live, and if in doubt about the results, get an independent educational evaluation. And then, get an advocate who knows how to help you get what your child needs as quickly as possible, before problems mount up.
Here’s an excellent article from Wrightslaw Way blog, with comments from parents and teachers, on what to do if you find yourself in this gray area:
https://www.wrightslaw.com/blog/child-is-aggressive-will-special-ed-help/