As Boston Mayor Marty Walsh seeks a second mayoral term, he’s making some bold claims about how safe the city is.
 
On Greater Boston on April 25, for example, Walsh  told Jim Braude that Boston is the “safest city, midsize city, in America.” On April 30, at a campaign stop in Dorchester, the mayor went even further, labeling Boston “the safest city in all of America” — a description that was subsequently  tweeted out by Walsh’s campaign manager, John Laadt.
 
A few days later, Boston suffered a  spate of homicides that the mayor couldn’t possibly have foreseen when he made those statements. Even without that rash of murders, though, Walsh’s claims would have been questionable.
 
"We are safe — much safer than most cities,” says James Alan Fox, a Northeastern University criminologist who’s been monitoring crime in Boston for decades. “But to claim top spot? Not so much.”
 
According to  federal data, Fox notes, Boston’s homicide rate in 2015 was 5.7 per hundred thousand residents. Among cities with more than half a million residents, that was eighth lowest — quite good, especially compared to cities like Baltimore, Chicago, and Detroit, but still higher than cities including Seattle, San Diego, and New York City.
 
And, Fox points out, “We don’t do so well in robbery and aggravated assault.” In 2015, Boston ranked 19th and 21st, respectively, in those categories.
 
So what’s behind that “safest city” claim? When I sat down with the mayor and police commissioner Bill Evans recently, Walsh began his explanation by showing me a graphic comparing Boston’s total homicide count last year to several other cities he considers comparable.
 
“This is 2016 homicide — Boston, Denver, Oklahoma City, Lousville, Washington [D.C.],  Milwaukee, New Orleans, Memphis, Baltimore. They’re all pretty much roughly our size…Seattle also," the mayor said. "We had the second-lowest of all those in homicides last year.” (For the record, Seattle had the lowest tally in that group.)
 
But if 2016 was a good year, what about 2015? Or 2014, when Boston’s murder rate was 8.1 per 100,000 residents, and the city’s overall violent-crime rate was higher than Tucson, Denver, Louisville, and Charlotte, among others?
 
When I brought up those numbers, Walsh shifted gears, arguing that urban vitality should be factored into the city-safety equation.
 
“The population growth we’ve had in our city the last three years, the job creation last three years, the amount of development going on in our city, the amount of housing we’re building — some of those cities don’t have what we have going on,” he said.
 
For his part, Evans urged me to compare Boston now to Boston a decade ago — citing a drop in Part One crimes, a category that comprises eight grave offenses, including murder and arson.
 
“I have a graph here,” Evans said, gesturing to a visual of his own. “31,479 Part One crimes in 2007. And it’s like a ski slope. The numbers continue going down. Last year, we had under 20,000.”
 
And, like his boss, Evans suggested that I take another subjective consideration into account.
 
“I don’t think anyone does a better job working with the community, being out there,” Evans said.
 
“I think when we say we’re the safest city, not only the numbers, but people’s sense of the impact the police have on the community go into effect, too.”
 
All of which suggests two big takeaways. When it comes to safety and crime, Walsh has a compelling story to tell. But it’s not nearly as clear cut as he likes to suggest.
 
And that, in turn, raises an obvious question: why not drop that “safest city” catch phrase in favor of a description that’s both more nuanced and more accurate?
 
At first, Walsh wouldn’t hear of it.
 
“I’m going to continue saying that, because we are a safe city,” he said. “Put us up against anybody.”
 
But a few minutes later, as I asked Evans if he’d continue using that descriptor, too, the mayor had a change of heart.
 
“I’ll come up with a different saying so you don’t hit me on it,” Walsh said. “How’s that?”