The quest for truth and justice has taken self-proclaimed “street-cop” Joe Slemko to places he said he could never have dreamed of when he joined the Edmonton police 29 years ago.
The bloodstain pattern analysis expert, forensic consultant and former crime scene investigator held an audience of law students spellbound on Feb. 3 as he recounted the highs and lows of that journey at the Bennett Jones Lecture Theatre at the University of Calgary.
In seven years as an Edmonton CSI, he investigated 150 murder and attempted murder cases and has since tackled another 300 as a private consultant. As an expert in blood spatter, he measures the pattern, volume and velocity of spilled blood to offer an interpretation of what happened — and often whodunit — at a crime scene.
“I’ve seen the good, the bad and the ugly,” said Slemko, who still loves being out on the street as a patrol constable when he isn’t giving expert testimony at trials around the world. “I’ve seen about everything you can see as to what humans are capable of doing to each other.”
As a witness at wrongful conviction actions, his testimony has resulted in some high-profile acquittals. He has testified for the prosecution and for the defence. In some instances his testimony broke the unwritten code that a policeman shouldn’t testify against the credibility of evidence gathered by police organizations, even when he is working on his own time.
As a private consultant, Slemko provides his services for wrongful conviction cases for free and has paid for most of his extensive training.
His experiences have revealed the detrimental impact of an “us against them” mentality held by some police, lawyers and forensic experts, he said. “That’s where the justice system gets off track.”
Bias can lead to tunnel vision
The cultural perspective of too many lawyers and police is that winning the battle is what going to court is all about, said the blunt-spoken officer. That bias often leads to tunnel vision that gets in the way of the pursuit of truth and justice, he argued. “It’s human nature — we all have biases … It’s whether we recognize those biases and are able to control them” that is crucial, he told the prospective lawyers.
He outlined the many ways bias impacts the legal process, such as when investigators, prosecutors and expert witnesses act as advocates instead of objective experts who operate based purely on the facts, regardless of which side will benefit.
Bias can be the result of loyalty to police agencies, co-workers or victims, he said, acknowledging the grueling conditions under which his colleagues must often work. It can result when investigators unwittingly look only for evidence that supports their opinion of guilt and may be unwilling to change their view because it might undermine their credibility.
It’s up to both prosecution and defence lawyers to “ensure the evidence presented to the triers of fact, the judge and jury, is the best available evidence and sometimes that means challenging experts, not only on their opinions, but the biases that may have influenced their opinions.”