Dr. Perl said that methylamphetamine in a high enough concentration could lead to death, usually from cardiac arrest or stroke, depending on factors such as how often the person used the drug and underlying health conditions. .
“The most important thing is the dose, but tolerance also plays a huge role,” she said.
She agreed that the level in Mr. Roberts’ system was higher than the average concentration reported in fatal cases.
Dr Perl said it was ‘highly likely’ that Mr Roberts’ driving skills were impaired by the amount of methylamphetamine in his system, with the drug also explaining the way he drove before the accident, including the speed and driving without headlights on.
Allan Cala, who performed the autopsy on Mr Roberts, said he concluded no natural disease had caused the death, the cause being mechanical or traumatic asphyxiation from being trapped under the police car.
Dr Cala said the asphyxiation could have been exacerbated by the backpack Mr Roberts was carrying, which could have pinned him between the car and the road.
The pathologist was asked about a report by a second pathologist, Johan Duflou, who said Mr Roberts did not show the typical signs of traumatic asphyxia and ‘the role of methamphetamine toxicity in causing the death does not appear have been sufficiently taken into account”.
Dr Cala acknowledged that the drug was present in Mr Roberts’ system at a ‘high to very high’ concentration, but disagreed with Prof Duflou’s suggestion that he had not taken enough take this consideration into account.
“I considered methamphetamine and its possible effects on the deceased,” Dr Cala said. “I didn’t feel like that essentially played a part in the death of this man.
“As I said in my report, which I stand by, this man – even if he had no drugs on board – could have died in exactly the same way.”
Dr Cala said he did not mention methamphetamine in his final report as a contributing factor to the death, as he was told that Mr Roberts was “severely” framed.
The trial continues.
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