This local news video has more details on the attack that left a baby critically injured. It now appears that the raccoons were not pets, but possibly had been habituated to human contact through repeated feeding.
As reported earlier, authorities have ordered rabies tests, but that would seem to be a mere formality; this is clearly a predatory attack. The animals used strategy to reach the child and eventually retreated from an attack. The choice of prey was highly unusual, but everything else about their actions is normal raccoon behavior.