Presence of drug cited by Crown as potentially lethal to Myles Gray couldn't be confirmed, toxicologist says

A toxicologist with the B.C. Centre for Disease Control (BCCDC) said a natural stimulant cited by Crown prosecutors as a potential cause of Myles Gray's death following a violent struggle with police cannot be confirmed with certainty as having actually been in his bloodstream. 

Aaron Shapiro told a coroner's inquest Wednesday an initial toxicology screen found Gray might have had mitragynine, also known as kratom, in his system when he died after being beaten by Vancouver police officers in 2015, but another analysis in 2016 showed there was only a small quantity of the natural stimulant in his system, if any.

"There were some indications it was present, but it didn't meet all the criteria for us to say that it was there," said Shapiro, the associate scientific director of toxicology at the BCCDC.

"It could've been that it was just a low amount and below what the instrument at the time was capable of detecting, or it could've just been, basically, instrument noise."

The toxicologist's testimony comes after police officers involved in Gray's death told the inquest they perceived him as either intoxicated, high or using steroids on account of his "aggressive" behaviour, "superhuman strength," and unresponsiveness to pain as he was beaten.

Kratom is an herbal substance found in Southeast Asia. Shapiro said low doses can act as a stimulant, like caffeine, while higher concentrations can have a similar effect to opioids.

A 2020 report from Crown counsel announcing the prosecutor's decision not to charge police officers said kratom might have been a contributing factor in Gray's death. 

On Wednesday, Shapiro said he reviewed the raw toxicology data in preparation for his testimony and subsequently changed the report because it was his professional finding that the kratom, if present, wouldn't have been at a level to be considered toxic or deadly.

"What this means is that the drug was either not present in the sample or it means that the drug was present at a concentration that was below our instruments' ability to detect it,'' he said.

"Unfortunately, I can't tell the difference between those two scenarios.''

Shapiro, who was not working in B.C. at the time of Gray's death, said the original blood samples have since been destroyed in standard practice.

No follow-up done on possibility of THC

Shapiro said the initial toxicology screen looked for more than 200 drugs to find which substances might be present, but would need further testing to confirm.

He said the initial screen found no traces of alcohol, opioids or hallucinogens in Gray's blood. It did find the potential for tetrahydrocannabinol, or THC, but Shapiro said the second confirmation test was never done.

"I would say, yes, it should have been done," he said, testifying as an expert witness.

THC is the primary psychoactive substance found in marijuana and can stay in the body for weeks. Shapiro said Wednesday the drug "would not lead to" the behaviour police described.

He said there have been reports of people experiencing hallucinations and paranoia after using cannabis but said "those are more the exception than the rule" and tend to be limited to cases where people are using "massive quantities in a very short period of time."

"I can't say whether that was the case here because a confirmation wasn't done, and they didn't get a concentration, but I'd say it's unlikely [in Gray's case]," he said.

Shapiro said kratom is used recreationally. Some people use it for conditions like depression, anxiety or bipolar disorder, as it interacts with dopamine and serotonin in a similar fashion to some antipsychotic and antidepressant medications.

Gray's sister and family physician previously told the inquest he had been diagnosed with bipolar disorder as a teenager around 1999 but was believed to have been stable since. 

Shapiro said toxicology testing did not find any evidence of drugs to treat bipolar disorder in Gray's samples, but Shapiro noted such medication is typically prescribed to be taken at night — if Gray was treating the condition, the substance would've been out of Gray's system by the time he died the following afternoon.

More than half a dozen firefighters and paramedics who responded to the scene that summer afternoon testified Tuesday that Gray was visibly bruised on his face and parts of his body when they arrived on scene. One described him as being beaten as though he'd been in "battle," while a specialized paramedic said he could not initially tell Gray was a white man because of the discolouration to his skin.

Most of the 14 police officers who took the stand said they didn't notice any visible injuries or blood on Gray besides some bruising and redness.

Firefighters who were first on the scene from the Burnaby Fire Department told the inquest police delayed first responders' access to the scene. One paramedic said police hesitated to tell first responders about their use of force as they formulated a treatment plan, but two other paramedics said they could not recall any delay.

14 officers testify during 1st week of inquest

All of the officers who testified during the inquest have used similar language to describe Gray's "threatening" behaviour toward police during the struggle to restrain him.

They said Gray continued fighting after being pepper-sprayed, punched, kneed, kicked, struck with batons and placed in a chokehold. Several said he appeared as though he was on testosterone.

Shapiro said the lab screened for several anabolic steroids but did not find any such substances, though he noted testing of the day wasn't capable of detecting every steroid on the market.

Gray had been in Vancouver making a delivery to a florist's supply shop as part of his Sechelt, B.C.-based business operations. Police were initially called after residents reported an agitated man had sprayed a woman with a garden hose.

Four police officers and a paramedic have told the inquest they believed Gray was experiencing a condition called "excited delirium," a term describing a state of agitation and cited as an explanation for sudden, unexpected deaths during interactions with police.

Last week, presiding coroner Larry Marzinzik provided the jury with what he called a "cautionary note'' about the term.

He said, to his knowledge, most pathologists don't recognize the term as a cause of death. The coroner asked the jury to put less weight on evidence from a layperson, like an officer.

A medical expert will speak to the term on Thursday, as will personnel from the Independent Investigations Office of B.C.

A coroner's inquest does not make findings of legal responsibility, but the jury will make recommendations aimed at preventing similar deaths in the future.