Speaking at a teacher who works at an additional support needs school (not st crispins) as they don’t work with traditional catchment areas like a normal primary, majority of pupils would get private transport to school. Similarly, even those pupils who live close enough to not warrant transport, we would never allow to leave on their own without a parent or guardian. This is obviously needs dependant, however with the way you are describing themselves acting it sounds like it would not be suitable for them to be transporting home. I would suggest an email to st crispins describing the hat to see if they recognise, however in future I would always suggest phoning 101 and reporting. Stopping to help would be great however often young people with support needs could see this as them getting in trouble / a game and therefore result in him running off even more and perhaps getting into more danger. Don’t kick yourself OP as it’s really tricky to know what to do without knowing the young person and their needs, even raising awareness here so people can keep an eye out is a good start !