You then hear the same story from 2 other parents in school - same kind of incident in the near area of the school.
Obviously the kids could have made it up, misinterpreted the situation or something else. But, I know you wuold have full confidence in your child and believe that he/she was telling the truth. Also, obviously, there would be no case where anything illegal can be proved as nothing illegal happend and your child came home safe.
Would this change anything for you ? would you stay rational and logic about it and tell yourself that this was an incident that your child is not likely to experience again and since nothing bad happend it would be hysterical to act upon it.
Or, would you have a period of time where you would be worried - maybe even picking up your child from school, telling school personnel to keep an eye out, asking your child not to go on his/her own anymore etc. All those things would be against your principles - but would it change anything that this was now about your own child and not just a story you read in the newspaper ?