The prosecution has challenged a forensic psychiatrist's finding an alleged teenage car thief is unfit to plead.
In particular they want to know how an apparently illiterate, innumerate and intellectually impaired young man was able to obtain a learner driver licence.
Jermaine Goolagong is facing charges of car theft, riding or driving a motor vehicle without consent, drug possession, aggravated burglary and theft. They relate to the alleged thefts of four luxury cars in April and July, as well as a Kingston break-in.
The court previously heard four luxury or sports cars were stolen from Kingston and Kambah in April and July.
A Nissan Skyline was taken from outside a house in Kambah, while a Porsche Cayenne, a Porsche Boxster, and a Subaru Impreza WRX were taken from Kingston.
Then, while on bail for the first string of charges, he allegedly ran a red light earlier this month in an unroadworthy vehicle, crashing into some associates and fleeing the scene. He was subsequently charged with driving an unsafely maintained vehicle, driving an unregistered vehicle, driving an uninsured vehicle and being an unaccompanied learner driver.
At the time his strict bail conditions banned him from getting behind the wheel of a car, and his bail was later revoked.
Psychiatrist Graham George has found the 18-year-old was ''functioning well below a normal level'' and was unfit to plead.
The evidence, if accepted by the court, paves the way for charges against Goolagong to be dismissed because of his mental condition.
But prosecutor Shane Drumgold challenged the doctor's findings yesterday in the ACT Magistrates Court.
The court heard some of the doctor's findings were based on information from previous reports into Goolagong's capacity, including some going back to 2005 when he was just 12-years-old. But Dr George said he believed new tests would still reveal the same results.
At the hearing, Mr Drumgold produced a copy of the Australian Road Rules Handbook and presented it to the witness.
The prosecutor said the required test for a learner licence involved answering 35 questions drawn at random out of a 350 question pool.
''From someone with Mr Goolagong's purported level of understanding, is that consistent with potentially answering 34 of these questions right on the first attempt,'' Mr Drumgold asked.
But the psychiatrist said it was possible the accused had learned the skills and road rules needed to pass through ''visual memory''.
Magistrate Bernadette Boss adjourned the case until next month so more evidence could be presented. In the meantime, Goolagong is expected to make a bail application later this week.