Police at the scene before the search for the baby boy was called off later on Wednesday. (HANDOUT/SOUTH AUSTRALIA POLICE)Police at the scene before the search for the baby boy was called off later on Wednesday. On Wednesday afternoon, police called off a three-day search of land and sea for Ms Wright's three-month-old son, who also vanished on Monday. Authorities continue to investigate exactly how the tragedy unfolded, after revealing on Wednesday they were treating the incident as a murder-suicide. Less than two hours later, at 11.15am, police were alerted to an abandoned car left with its engine left running near Cape Northumberland.