He did not describe what that explanation would be.

Dr Alexander, referring to earlier comments Justice Mark Weinberg made to the jury, said Mr Gargasoulas was clearly ‘‘not well’’ but that Mr Gargasoulas believed he had ‘‘very important reasons’’ for what happened in Bourke Street.

The court had earlier been told by Dr Alexander and Director of Public Prosecutions Kerri Judd, QC, that the facts of the case – including Mr Gargasoulas’ identity as the driver of the stolen car used in the incident – were not in dispute.

As part of her opening argument, Ms Judd screened CCTV and other video footage allegedly showing Mr Gargasoulas striking down pedestrians along Bourke Street.

There were audible gasps in the courtroom as the footage was played. Some members of the victims’ families chose to leave the court before it was screened.

Ms Judd later described how each of the 33 victims came to be in the street that day and the circumstances under which they were struck, and injured or killed.

‘‘He deliberately drove into pedestrians. In a period lasting only a minute the accused left a trail of destruction,’’ Ms Judd said.

The court was told witnesses described Mr Gargasoulas’ conduct as ‘‘relentless’’ and he ‘‘just mowed people down’’.

The prosecution also read out parts of witness statements and copies of text messages that allegedly showed Mr Gargasoulas repeatedly threatening to hurt people with a car if he was approached by police.

In the early hours of January 20 last year – the morning of the Bourke Street incident – after believing he had killed his brother Angelo with a large kitchen knife, Mr Gargasoulas allegedly told an associate: ‘‘I’m going to do something drastic, take everyone out. Watch, you’ll see me tonight on the news’’.

Watch, you’ll see me tonight on the news.

James Gargasoulas

Later, Mr Gargasoulas sent a text message to one officer pursuing him that read: ‘‘I’m telling you, you’re making a big mistake’’.

As he approached Flinders Street Station in the CBD, the officer texted: ‘‘Don’t do this’’.

The court heard Mr Gargasoulas had been using the drug ice the day before the Bourke Street incident and that he had been a user since 2016.

‘‘At the time of the offences, Mr Gargasoulas was in a drug-induced psychosis,’’ Dr Alexander told the court but he noted that drug use does not amount to a defence to the charges.

‘‘This is sad, tragic and emotional case,’’ he said.

Justice Weinberg addressed Mr Gargasoulas’ drug use during the instructions he gave to the jury after they were empanelled on Wednesday: ‘‘You should know, and I will tell you in more detail ultimately, that delusions brought about by the use of drugs, self-induced drugs, such as ice, provide no defence to any criminal charge and do not affect criminal responsibility.’’

The case continues.