The Ninja Turtle scampered up to me and opened his plastic bag.

"Weren't you already here before?" I asked. After shaking his head a little too enthusiastically, he admitted, "They said we're supposed to go around again." The child took great care to thank me for the additional Starburst and proceeded to scamper down the elementary school hallway, where another volunteer was waiting with a cardboard box filled with candy.

It was a Tuesday night in Detroit, and even though classes had been over for hours, this officially sanctioned school activity was how plenty of local kids were getting a taste of Halloween.

Among other things, Halloween in America is indelibly linked to images of miniature skeletons or vampires scuttling from door to door, begging for candy from their half-amused neighbors. But in some communities, that paradigm seems to be fading in favor of those same miniature Ninja Turtles or Superheroes making their way from car to car in a well-lit parking lot, or desk to desk in a school hallway. The basic idea—usually dubbed "Trunk or Treat" or "Halloween tailgating"—isn't exactly a novel one, but it seems to have gained a new foothold in urban centers across the US in recent years, with dozens of such events advertised this week in cities like Detroit, Chicago, and Pittsburgh.

"There are so many going on that it's impossible to keep track of them," said Melia Howard, a precinct delegate for Physically Fit 4 Hoops, a Detroit nonprofit that hosted a trunk-or-treat in a rec-center parking lot on the east side of the city Tuesday.

A trunk or treat chaperone at Farwell Recreation Center in Detroit

The precise origins of trunk-or-treating are in some dispute, though the few sources that attempt to document it sometimes point to members of the Church of Latter-Day Saints—a.k.a. Mormons—in Utah. As the trend has gone a bit more mainstream over the past decade or so, denizens of Small Town USA have introduced the practice for a variety of reasons, including the sheer distance between houses. But while milling around a parking lot might sound a bit underwhelming or just plain lame, both organizers and trunk-goers said its emergence in Detroit reflected the economic and social problems looming largest for their city.

"This is our third year. We put this on because people just don't trick-or-treat in Detroit anymore, at least on the east side," Howard said. "Here, kids don't have the opportunity to go door to door. Neighbors don't give out candy. Some people just don't feel safe."

Her perspective was echoed by that of James Payne, a teacher at the elementary school on the north side where I helped hand out candy. "When I was growing up, we didn't go to events like this. We would attend events at our local rec center, but besides that, we mostly trick-or-treated around our neighborhood. I just moved back last year, after 18 years in California, and in my neighborhood, there's only seven or eight people who I remember from when I was a kid who are still around. Safety is definitely an issue."

"This replaces trick-or-treating for us," Monica, an area parent who preferred not to give her last name and attended the school trunk-or-treat. "The time that we live in now is much different from when I was growing up."

Of course, Halloween has always lit an acute sense of danger and fear for some Americans—sometimes bordering on hysteria. Its alleged origins as a pagan holiday—still disputed—have won it a legacy of skepticism from religious officials and everyday practitioners alike. Such dealings might seem almost comical to the godless heathens among us, but in the small Southern town where I grew up, it was serious business; I can still recall one sunny afternoon in second grade when one of my best friends informed me that my Grim Reaper garb went "against God," and I was thus banished from his household forevermore. (His parents forgot about it after a month.)

Still, according to Nick Rogers, a professor at York University in Toronto and author of the book Halloween: From Pagan Ritual to Party Night, the idea of trick-or-treating as a dangerous activity is well engrained in American culture. Citing the work of sociologist Joel Best, Rogers explained the concept of "Halloween sadism."

"It was a scare in the 60s and 70s, and it just billowed up from there," he said. "Contaminated candies, razors in the apples, things like that... It's never gone away, but it's had to make a comeback."

In cities like Detroit, it's safe to say parents' concerns are a bit more corporeal than the vague possibility of cyanide being in their kid's Reese's Cup. Though the city's crime rate has been trending downward amid a comeback of sorts in recent years, some interviewees cited the simmering specter of "Devil's Night," the evening of October 30, when arsonists have a history of setting conflagrations across the city, in some cases apparently for insurance money. (Community officials managed to staunch the practice starting in the mid 90s, and it's been fairly quiet ever since).

Leaving "Devil's Night" and safety concerns aside, interest in trunk-or-treating in Detroit also seemed to be the product of a more fundamental sense of social isolation.

"It's more of a demographic transition than anything," Howard said. "People are getting older, they don't know their neighbors as well as they used to, they don't feel like getting the door. We're just trying to adapt to that reality."