It's definitely environmental. Why not take a couple thousand kids aside and try something different and just see.
All this story is dong is comparing apples and oranges. The parents who have autistic children deserve better than this.
Manny of the kids doing shootings might fit the term "autistic spectrum" but due to privacy, it's not readily exposed. Some have been put on SSRI's and the news will never tell you. 30-40 million Americans take SSRI's today. Once you get on them you can hardly stop taking them. ALL,....ALL school shooters in the recent past since the 80's were either on SSRI's or getting off of them. Columbine is a textbook example. Were they autistic? We don't know, but they were on SSRI's. They had difficulty relating to others. Did this guy in Fla. relate to those he murdered? He was on SSRI's. People on SSRI's don't cry. They don't have feelings for others. My father in law was on SSRI's and his wife of 45 years died. He didn't ever cry until he died. He even stated that he couldn't cry for her. He had feelings of suicide.
I've seen people try to stop taking SSRI's and it looks like they are sopping heroine. If you complain to the doctor, they say why are you stopping taking them? If you want to be an unfeeling Stepford wife for the rest of your life, keep taking them.
I guess you and your fellow flat-Earthers never heard of all of the kids in iron lungs before Salk developed a polio vaccine, or about how smallpox would wipe out a large fraction of entire British towns before Jenner developed his cowpox-based vaccine.
As to your s-called 'reasoning" that says "My kid has autism. My kid was once vaccinated. Therefore the vaccine caused his autism", it's more or less equivalent to the thinking behind, "I twisted my ankle this morning while working in the yard. Last week, I drank some iced tea. Therefore, iced tea caused me to twist my ankle." Good luck.