My Autistic Brother Dropped Off at the Wrong Address by School Bus, Leaving My Family Searching for Answers

My younger brother (20m) is autistic and nonverbal. After he graduated from high school, we enrolled him in a community transition program through the public school district. Today, he participated in a worksite training excursion either with or alongside the school through the Red Cross. My family is not clear on many of the details surrounding the incident. Long story short, after he didn’t come home on the school bus, my mother called the school to ask where he was. After asking us if he had even shown up that morning, they informed my mom that he was “missing” and that they were going to go get him. He was brought home around 5:30 PM PST; he had left that morning at approximately 7:50 AM. The school district told us that there had been a mix-up, and he was mistakenly dropped off at another child’s address, where he had been with the family since then. This story doesn’t make sense, especially since we separately contacted the bus driver who brought him home, and she told us she was sent to an address and found him standing alone on the street. My brother is autistic but very detail-oriented and would never get off at a stop that wasn’t his. The whole thing is confusing. The oddest part was the school telling us that a random family had willingly taken him in without asking any questions. Unfortunately, we don’t have the staff’s mismatched claims in writing. My mom called the police as soon as he was confirmed as missing, but we haven’t received any updates. Should we contact a lawyer? What should be our family’s next steps?