We had a great day at the park with our autistic son, until someone called the police - The Washington Post

We had a great day at the park with our autistic son, until someone called the police - The Washington Post:
"It had been a good day at the park.
A miracle day, in fact, for our family. 
Our 5-year-old son, who is moderately autistic and prone to violent outbursts and self-injurious behavior, had sailed through the outing without a meltdown.
So it was all the more shocking when the police approached us.
It was a Sunday, four days before Thanksgiving, and my mom was in town visiting.
My son had a good morning, and feeling encouraged by that, we selected a new park to visit, the boardwalk on Lady Bird Lake in Austin.
We had been struggling for weeks with getting (and keeping) my son dressed. He had been in a protest phase with his clothes and diaper, but on this morning, he not only let us dress him, he even selected his pants. Sure, they were a size too small and the legs crept up like high waters, but we were thrilled he had chosen them himself.
[About that time I was accused of child abuse]...
Read on!!