The downward trend came as the agency reported serious crime in general fell to its lowest relative level since 1969 — marking 11 straight years of declines.
What accounts for the downward trend is not easily explained, said criminologist Anthony Doob.
"People have been looking at this for a long time but haven't come up with completely adequate answers," said Doob, a professor at the University of Toronto.
"It may have to do with some changes in the demographic makeup of Canada but that's small — that certainly doesn't account for it."
According to StatsCan, police reported about 369,500 violent incidents in 2014 — 15,000 fewer than in 2013 — representing a five per cent decrease. While homicides edged up to 516 from 512 a year earlier, the rate remained unchanged relative to Canada's population size.
Violent crime accounted for about one in five police-reported Criminal Code offences last year.
Among provinces and territories, only Yukon, Prince Edward Island and Alberta saw increases in violent crime — mostly because of more murders.
Doob said violent crime appears to have been decreasing across western countries for ages — with a still unexplained upward blip in the 1960s and 1970s. What's clear, he said, is that politics and government anti-crime legislation have little to do with it.
"The prime minister last fall took credit for the decrease and I never understood if he was taking credit for the decrease that started in 1991," Doob said. "Whatever it is that's doing it is pretty broad."
About one-third of urban areas saw crime rates rise last year, with Saskatoon showing the biggest jump at 10 per cent. Montreal had the biggest drop at nine per cent.
It was the first time that Saskatoon had the highest rate in the country — taking over from longtime leader Regina — mostly due to big increase in breaking and entering, StatsCan said. In contrast, Barrie, Ont., recorded the lowest crime rate among urban centres, despite a small rise.
Among the provinces, Saskatchewan had the highest crime rate last year while Quebec had the lowest rate.
When it comes to measuring the quantity of serious crime relative to Canada's population, the rate was down three per cent from 2013, StatsCan said.
Serious police-reported crime fell to its lowest level since 1998, when the agency started tracking what it calls its crime severity index.
In all, police services reported almost 1.8 million Criminal Code incidents in 2014 — excluding traffic offences — with lower numbers for most offences.
The agency attributed the lower numbers mostly to fewer break-ins and robberies but said some offences, such as child pornography and terrorism, bucked the downward trend.
Statistics Canada said the increase in sex crimes against children reported last year was primarily the result of incidents of luring a child via computer and could be attributed to specialized police units targeting such offences.