The public usually thinks of serial killers as ruthless lone predators, who hunt down their victims in solitude.
But in fact, more than 20 percent of these types of murders are perpetrated by teams of two or more.
A 2004 study of 49 cases, involving 114 offenders, found that 26 percent of all the serial killers were operating in tandem with others. Women were the partners in 17 of these cases.
So if it turns out that fugitive Port Alberni teenagers Kam McLeod and Bryer Schmegelsky are team serial killers, that would be far from unprecedented.
The childhood friends and former Walmart employees have been named as suspects in the deaths of three people in northern B.C.
Among the dead are American tourist Chynna Deese and her Australian boyfriend, Lucas Fowler, who were gunned down along the Alaska Highway.
A third unidentified male's body was found south of Dease Lake, two kilometres from a burned-out pickup truck driven by McLeod and Schmegelsky.
He has analyzed hundreds of serial-killer teams and found that in each instance, one person was in control.
Paul Bernardo and Karla Homolka are the most notorious pair of serial killers in Canadian history.
Here in British Columbia, a grisly team killing occurred in the double murder of Sharon Huenemann and her mother, Doris Leatherbarrow, in Tsawwassen in 1992.
The mastermind was Huenemann's 18-year-old son Darren, who wanted their money in an inheritance.
Darren Huenemann, who has since changed his surname to Gowan, hired two 17-year-old friends, Derik Lord and David Muir, to commit the crimes.
In pairs, one serial killer is usually dominant
In the United States, the so-called Lonely Hearts Killers, Martha Beck and Ray Fernandez, were suspected of murdering up to 20 people in the United States from 1947 to 1949.
Three decades later, the Hillside Stranglers—Kenneth Bianchi and Angelo Buono—terrorized the Los Angeles area in 1977 and 1978, killing at least 10 people in tandem.
Another famous pair of serial killers, John Allen Muhammad, 42, and Lee Boyd Malvo, 17, gunned down 10 people in the Washington, D.C. area in 2002.
Serial killer expert and former prison psychologist Al Carlisle told Psychology Today in 2014 that the dominant person in any pair of serial killers "needs the follower's total loyalty in order to validate him or herself".
"The subservient follower needs the power and authority of the dominant person," Carlisle continued, "so he or she attempts to become that person's shadow and to mirror the dominant person's beliefs and ethics."
If McLeod and Schmegelsky fit this pattern, the question then becomes which one is the dominant partner. And will the subservient one be more likely to cooperate with prosecutors if the attachment is broken?
Leopold and Loeb case riveted the world
The most famous murderous pair in American history might be Nathan Freudenthal Leopold and Richard Albert Loeb, two wealthy students who kidnapped and murdered a 14-year-old male in Chicago in 1924.
Like McLeod and Schmegelsky, Leopold and Loeb were 19 and 18 years old, respectively, at the time of the so-called thrill killing of Robert Franks.
The Leopold and Loeb murders have been adapted into plays, books, and popular movies, including Alfred Hitchcock's Rope and Richard Fleischer's Compulsion.
In 1924, the Chicago Tribune reported that Leopold seemed to be the more dominant member of the pair. He claimed to speak five languages and was fascinated by philosopher Friedrich Nietzsche's writings about "supermen".
Loeb, the son of a Sears vice president, financed the crime.
Loeb reportedly sobbed during his confession, which came first, and the pair received life sentences.
Thanks to brilliant arguments by their famous lawyer, Clarence Darrow, they avoided receiving the death penalty, though Loeb died in a prison stabbing in 1936.
Leopold was eventually released on parole in 1958 and died in Puerto Rico in 1971.
The Toyota Rav 4 that McLeod and Schmegelsky crossed several provinces in was discovered burned out in area around Gillam, Manitoba.
Photos of Shmegelsky were sent to over a video game network to another user, and then published by the Globe and Mail. One shows the teen wearing battle fatigues and carrying a weapon.
Another image shows Nazi memorabilia.