If you think a child is being abused, report it. The burden of proof does not fall on you, you just need to have a reasonable suspicion. At worst, maybe your report could ruin a parent's day. But your phone call could potentially save a child's life.
To report suspected child abuse, neglect or abandonment call:
Statewide in Idaho: 855-552-KIDS (5437)
Treasure Valley: 208-334-KIDS (5437)
2-1-1 or local law enforcement