The attack happened early last Wednesday near the Child Health Centre on Mead Street, where the family vehicle was parked.
A student from Kalamunda Senior High School ” seen with a group of about four others ” allegedly used a slingshot to sling a rock through the window, smashing it and almost hitting the baby, who was in the back seat.
Paul Gregory, whose wife was driving the vehicle, immediately reported the incident to both the police and the school.
Police are now conducting an investigation.
Kalamunda Senior High School principal Kathy Ritchie said she was in the process of identifying who slung the rock.
‘I am deeply disturbed at this incident, which allegedly involved one of our students,’ she said.
‘I am relieved to hear that the baby was unharmed. We are working with police to identify the student involved.’
Mrs Ritchie said behaviour of this type was unacceptable in the community.
‘The school will take appropriate disciplinary action as soon as the student is identified,’ she said.
Mr Gregory said the use of a slingshot was of particular concern.
‘Someone needs to be punished for carrying a weapon to the school,’ he said.
‘There are damages to our vehicle that someone needs to pay for.’
Mr Gregory’s wife, who asked not to be named, said she was still shaken by the incident and felt lucky that nobody was injured.
‘What saved the baby was the fact that we have tinting on the windows,’ she said.
‘The rock smashed through the window but the tinting held it together.
‘If it hadn’t been so strong, it would have hit the baby.’