'It’s not people who come across town to do this. It’s people who know each other who kill each other.'

Crime is down in Atlanta since Mayor Kasim Reed took office in 2010. We were reminded of that — again — by Police Chief George Turner in a press conference Wednesday.

In fact, it has dropped 30 percent since 2009, according to the department’s figures. It’s even down 4 percent this year compared to last year.

But Reed and Turner did not gather dozens of APD commanders and have them stand in front of cameras in their dress blues to crow about such achievements.

No, something bad is a-brewing in Atlanta. Homicides are up in the past 28 days. Way up, like 200 percent. That’s 15 body bags, compared to five. And shootings have increased 42 percent in that time.

Sure, it’s summer and people do awful things when the mercury rises. But it was hot last year, too.

One month does not a trend make, but the murder rate is up 25 percent so far this year and shootings (they only measure when someone gets hit) are up 5 percent.

So what’s up?

Short answer: They really don’t know. When one person decides to shoot or stab or bludgeon to death another person, there are a myriad of reasons, most of them deeply personal. So it’s hard for a mayor or a police chief to talk with any specificity. It might be gang rivalries. Or bad upbringing. Or too many guns in the wrong hands. But those reasons are always there.

Residents get nervous when they flip on the TV and see blue lights, crime tape and evidence technicians collecting shell casings. Assurances that crime is down 4 percent ring hollow.

So they offer up “Operation Whiplash,” the newest initiative that promises police will get serious as the crack of a whip. Or a neck injury that brings about a plaintiff’s attorneys. Either way, watch out, bad guys.

“It’s all hands on deck,” vowed Hizzoner, with his best I’m not-playin’ face. He talked about the “tip of the spear” and “robust” efforts and that cops won’t only be “tough,” they’ll be “smart.”

The department will shuffle its forces and have 45 uniform cops focusing on problem areas to ferret out gun violence. Another 20 will “gather intelligence” and address “community concerns.”

I wanted to ask from where these re-deployments were coming? Obviously, the officers were already on the city payroll.

But the mayor and his commanders left before taking lots of questions.

After the session, I noticed Maj. Jeff Glazier lingering off to the side and it became apparent he was left behind by higher-ups to offer some explanation.

I suppose he drew the short straw because he commands Zone 3 on the south side and 10 of those 15 recent deaths occurred on his turf.

“Every other category (of crime) is down” in his zone, he said, with a tone of genuine befuddlement.

I met Glazier in December 2014 after a rash of shootings at a troublesome corner in the Pittsburgh neighborhood just south of downtown. Glazier and his forces were flooding the zone there but, he admitted, they were playing Whac-a-Mole — except these were really mean, violent gophers.

His hard-nosed and focused approach worked. Zone 3 won APD’s Crime Reduction Award last year, with a 7 percent drop in crime, the best in the city. Murders dropped from 30 in 2014 to 22 last year. Glazier looked real smart.

But this year, there have been 22 homicides so far, equaling all of last year. And, so, last year’s Crime Reduction Award winner is left behind to talk to the media.

“You’d think the reduction in robberies, burglaries and other crimes would bring down homicides,” he said. “Officers put their lives on the line to protect people they’ve never met. We track crime by the hour.”

He waved off theories like the so-called “Ferguson effect” have hampered crime fighting. That theory posits that a public backlash against police shootings have caused cops to back off doing their jobs, emboldening the ne’er-do-wells.

“The guys are engaged in what they are doing,” he said.

I traveled Pittsburgh, a bleak community with numerous vacant houses and a dearth of legal commerce, and talked to numerous residents.

One fellow walking down McDaniel Street with a 9 mm on his hip — he said his name is Kyle Bey and he works in security — says it’s best to mind your own business, which is a common strategy there for survival.

Another oft-heard observation is “those young folks just don’t care,” as if a wildly unpredictable force surges through the community.

“It’s territorial young people with hot tempers,” said Thomas Webster, a middle-aged resident. “It’s not people who come across town to do this. It’s people who know each other who kill each other. A man feels braver with a gun in his pocket: ‘Hey, you bumped into me! You stepped on my new tennis shoes!’”

The perceived slights are many and the recourse is often swift and final.

Police have their work cut out for them this summer.