TOXICOLOGIST CAN'T SAY FOR SURE IF COCAINE CAUSED DAVIDSON'S DEATH

An expert witness on toxicology couldn't say if the level of cocaine
in a truck driver who died after being subdued by police in a
cornfield could have been fatal.

Jeremy Gamble, a forensic toxicologist with the Centre of Forensic
Sciences in Toronto, was one of five witnesses to testify Monday at a
coroner's inquest into the November 15, 2003, death of Brockville's
William Stephen Davidson.

Gamble said blood tested from Davidson's heart revealed a level of
0.18 milligrams of cocaine in one millilitre of blood.

In addition, the level of benzoylecomine, a product that results from
the breakdown of cocaine, tested at 0.61 milligrams per one millilitre
of blood, he testified.

According to most studies, the levels overlap the range between
incidental and the likely cause of a fatality, said Gamble.

"We can't say, just taking one piece of the puzzle, what the cause of
death was."

Gamble was also non-definitive about the question of cocaine-induced
excited delirium, a potentially fatal state experienced by people with
mental illness, under the influence of drugs or going through alcohol
withdrawal.

"The levels in this case are consistent with that (when) taking the
entire scenario into (consideration)," he said.

He said the delirium includes agitation, paranoia and a tendency to
violence along with exhibitions of superhuman strength and resistance
to pain.

Gamble said cocaine stimulates the central nervous system and, as the
heart rate increases, the ability of blood vessels to carry oxygen is
diminished.

"During exercise, it's not a big issue (when the heart pumps faster)
because the blood vessels dilate, but with cocaine toxicity, the blood
vessels constrict and it could lead to a heart attack.

"In the case of a struggle ... that puts even more stress on the
heart."

Previous evidence indicated Davidson was driving erratically in a
Wills Transfer truck, without the trailer, northbound on County Road
29 from Brockville to Addison when it veered left and sustained damage
after striking the west bank of a ditch before coming to a stop in the
cornfield.

Along the way, the vehicle sheered a strip off the driver's side of a
southbound car near the Seaway Gas outlet. The two occupants received
non-life-threatening injuries.

A subsequent police pursuit followed during which, officers testified,
the truck was constantly swerving between lanes.

The truck nearly struck another OPP constable standing near a cruiser
while avoiding a spike belt at the intersection of county roads 29 and
42.

The chase ended when the vehicle entered a cornfield on the property
of Gordon De Roos and came to a halt among unharvested rows of corn.

Monday's first witness, Smiths Falls feed-mill owner Mark Schokking,
testified he arrived with others from De Roos's farm after hearing the
commotion and saw Davidson face down on the ground with two officers
attempting to subdue him and apply handcuffs.

"They were trying to keep him down and telling him to calm down, calm
down," he said, noting he was standing about 20 feet away.

"(Davidson) didn't say anything coherent. He was trying to get up and
making grunting noises like when somebody's trying to lift something
heavy. He wasn't co-operating at all."

Schokking said another officer asked them to leave the area and later
shouted at them to call 911 because Davidson had gone into cardiac
arrest.

He said the officer called out moments later to say the 911 call had
already been placed.

Also testifying was a doctor on contract with Corrections Canada who
had one meeting with Davidson when he was an inmate at the Joyceville
Institution.

Dr. Ellen McKeough said she had no memory of meeting Davidson but her
records indicated he was abusive toward her when she denied him a
prescription for Tylenol 3 to deal with an arthritic ankle.

The toxicology report presented earlier indicated there were trace
levels of codeine, an ingredient in Tylenol 3, found in Davidson's
system.

The five-member jury also heard testimony from two instructors who
train police in the use of force, one from the OPP and the other from
the RCMP.

Both said, given what they know of the situation, the officers
involved did not use excessive force in trying to arrest Davidson.

David Carruthers, counsel for the coroner's office, asked Staff
Sergeant Steve Kruszelnyckyj of the RCMP, on behalf of Davidson's
family, if there were any other ways of dealing with Davidson besides
confronting him.

"I really can't think of any alternatives at that point," he answered.