Disappearance of Jason Shannon

Darren Jason Shannon, an 11-month-old baby, disappeared on 9 June 1973 in the Adelaide suburb of Elizabeth West, South Australia. At the time, his parents Barry and Michelle Shannon were temporarily separated after Barry had hit Michelle, prompting her to move in with her parents on Blackdown Street in Elizabeth West. Barry had been visiting his son daily during the separation.

At approximately 7:15 pm on 9 June 1973, during one such access visit, Barry Shannon left the grandparents' home with baby Jason. Jason's maternal grandfather, Alfred Hinde, attempted to stop him and then gave chase by car but could not locate them. About two hours later, at approximately 9:15 pm, Barry Shannon was killed in a head-on collision with another vehicle on Main North Road near Roseworthy. The two occupants of the other vehicle were taken to the Royal Adelaide Hospital. Despite an extensive search of the crash site, baby Jason was not found, and his whereabouts could not be determined.

In the days following the crash, police said they still hoped to find Jason alive, though the two-hour gap between the abduction and the crash complicated the investigation. Michelle Shannon made a televised public appeal for help finding her son. The active search was called off on 15 June 1973, though detectives said they were following several leads. Michelle Shannon and her parents left Adelaide in 1974 and returned to the United Kingdom. She later remarried and is now known as Michelle Swift; in 2016 she said she still held a faint hope her son was alive, and in November 2015 she returned to the crash site to lay flowers.

Investigators have considered two principal theories. The first is that Barry Shannon killed his son and disposed of the body before deliberately causing the fatal crash to end his own life. The second is that he left the baby in an empty house or gave him to a friend or family member to raise secretly, a possibility given weight by the fact that Barry's parents had wanted Jason to live with them after the separation. As of 2016, the case was being investigated by the South Australia Police Major Crime Investigation Section as part of the long-term cold case initiative Operation Persist. Detective Sergeant Cameron Georg publicly appealed for information about the possibility that Jason had been given to someone to raise as their own. Police also examined whether the estates of Barry Shannon's parents or his brother were left to anyone matching Jason's age, without result, and looked into information regarding a close bond Barry had formed with a female patient at Fullarton Private Hospital, where he had been treated for mental illness.

Jason Shannon is listed by Crime Stoppers South Australia as missing, presumed murdered. A reward of up to $1 million is offered for information leading to a conviction over his suspected death or to the location of his remains.