Tunnel vision can significantly influence police investigations, say experts

In 2011, a rich man was bludgeoned to death in a small New Brunswick town.

High-profile, brutally violent and unprecedented in almost every way, it was the kind of case that could drag on and roil a community for years. Yet just hours after Richard Oland's body was discovered, Saint John police seemed to believe they had cornered the killer: Richard's son, Dennis Oland.

Eight years and two trials later, he was acquitted by a judge.

It appears the police were wrong. And the real killer remains free.

Suspected from day one

The documentary series The Oland Murder follows Dennis Oland and his defence team's journey to exoneration.

Tim Moore, a psychology professor at York University's Glendon College, regularly testifies in court as an expert witness, discussing areas in which "cognitive psychology intersects with the criminal justice system." Moore sat down with the producers to discuss the case.

After reviewing Oland's interrogation video, Moore says he believes Saint John police zeroed in on the son within hours of speaking with him, on the same day his father's body was found.

"It's my impression that he doesn't really become a suspect until towards the end of that second hour [of questioning]," Moore says. "And that seems to me to have been based on alleged inconsistencies in terms of what he was saying."

"It's hard to know from this video how much they know," he adds, "because sometimes the police exaggerate how much they know."

The interrogation video

Oland doesn't confess to the crime during his hours-long questioning, but he is visibly uncomfortable in the latter portion of the video, shrinking away from the detective. Moore says these signs of discomfort may be interpreted as guilt by investigators.

The problem with this perception? Many studies over the past 20 years have shown that supposed behavioural cues of deception and guilt are "invalid" and "unreliable," Moore says. Not even trained law enforcement professionals can accurately perceive when someone is lying.

"It's a scientifically bankrupt proposition to suppose that by studying someone's body language or mannerisms you can draw a legitimate conclusion about whether they're being deceptive or not," he says.

"I think that is worrisome from an investigative point of view, because now we have a detective who has inferred on the basis of very unreliable evidence — that is, body language — that the suspect is lying."

The influence of cognitive bias

The documentary producers also spoke with Keith Findley, an associate professor at the University of Wisconsin Law School and co-founder of the Wisconsin Innocence Project. Findley stressed that he can't comment on the Oland investigation specifically, but instead speaks to law enforcement practices more broadly and how they can be affected by cognitive bias. 

When social scientists talk about "cognitive biases," he explains, they're not talking about prejudice, but how humans naturally process large amounts of information. "We have all these shortcuts to thinking that tend to lead us to reach conclusions in one direction or another. And, in general, those are a really good thing."

Most of us tend to "draw conclusions fairly early, and then start looking for the evidence to support that conclusion," Findley continues. But this can also make it hard for us to move away from our initial assessments when they're wrong. 

"One of the problems with criminal investigations is that investigators tend to lock in on a suspect early on — and by definition, almost, that means before they really have proof, right?"

'Tunnel vision' in the justice system

In the criminal justice system, Findley says, "we talk about cognitive biases, but we tend to talk about [them] in terms of tunnel vision." "Tunnel vision" is a term used to describe when investigators are focusing on one theory or suspect — but inadvertently blocking out other possibilities and evidence.

"When we're investigating, we go out and look for other evidence that supports the conclusion," he says. "We also tend to recall evidence that supports the conclusion, and we tend to elevate insignificant evidence that supports the conclusion. Evidence that's inconsistent with that conclusion is either not sought, not remembered or is diminished in significance."

Relying on body language as evidence of deception is one thing that "could contribute to a degree of tunnel vision," says Moore. 

The 'celebrity' factor

Experts say high-profile cases can apply additional pressure on authorities during an investigation. 

"The more heinous the crime, the more pressure there is to convict, the more tendency there may be to cut corners, bend rules — even unwittingly," said Findley. 

He adds that certain features of the justice system can fail to challenge assumptions that might exist around a suspect's guilt. For instance, forensic laboratories often know who the suspect is and may be inclined to interpret evidence to support the conclusion, while other scientific fields rely on blind testing as a rule.

"We need to build institutional frameworks for recognizing that biases are at work and for doing the very best we can to shield us from them — instead of encouraging us to rely on them," he says.

The potential for catastrophic results

When wrongful convictions are examined, Findley says, "in almost every one of those cases, tunnel vision is a factor."

If human patterns of bias aren't challenged and investigative tunnel vision is left unchecked, the results can be catastrophic. In the justice system, after all, the stakes couldn't be higher.

"Innocent people can wind up being convicted," Findley says. "They can wind up being sentenced to long periods of time in prison. Of course, in places like the United States, they can be sentenced to death."