A jury in Australia is deadlocked over whether a man is mentally fit to stand trial on charges that he murdered six people by driving a car through a crowd of people in Melbourne, the country’s second largest city.

The Victoria state Supreme Court jury had heard conflicting expert evidence on the mental state of James “Dimitrious” Gargasoulas.

The jury of 12 deliberated for nearly four days before reporting on Friday that they could not reach a unanimous decision. A new jury will be selected.

Gargasoulas is charged with six counts of murder and 28 counts of attempted murder after allegedly driving a stolen car through pedestrians in central Bourke Street last year.

Two psychiatrists told the court the 28-year-old was unfit to stand trial, but a psychologist disagreed.