When a panicked stranger emailed me this past weekend to say that police in Cartersville, Georgia, had “locked up a hundred kids when they claimed to find less than an ounce of weed at a house party,” I didn’t need to ask if the kids were black. I already knew. Police departments across north Georgia, a region north of Atlanta where Cartersville is located, just aren’t that likely to arrest 100 white kids at a house party if they discovered less than an ounce of marijuana.

But that’s exactly what happened in Cartersville. When I searched for local news reports in Atlanta and found that police actually arrested, charged, and jailed these people — the overwhelming majority of them young and black — for marijuana possession, I was initially puzzled. Had all 70 of them possessed marijuana? Nope.

Many of the men and women who were arrested were then fired from their jobs after they were left in jail for days on end.

After claiming to find less than an ounce of weed in total — which has a street value of around $150 to $200 and would mean only a ticket in the nearby city of Atlanta — police in Cartersville charged all 70 people gathered for a birthday party — including men, women, boys, and girls, ranging from the ages of 15 to 31 — with drug possession and hauled them off to Bartow County Jail.

A pregnant woman said she was verbally abused and mistreated in jail. Another person said they were threatened with Tasers and locked in actual cages. Some of the attendees were military veterans and college students who were home for the holidays. Others were standout student athletes.

Many of these people’s lives will be ruined because of that small amount of marijuana. Scores of lawyers have been hired; nearly $100,000 in bail money was paid; and good people — who, for all we or the cops know, have never even smoked weed — are wondering if they are about to have a criminal record. Their mugshots were publicly released. Unable to afford bail, many of the men and women who were arrested were then fired from their jobs after they were left in jail for days on end.

“I thought they were just gonna shut the party down and everybody was going to go home,” said Deja Heard, who had rented the home on Airbnb for her 21st birthday. And the partygoers didn’t even understand what was happening: “We did not know what we were going to jail for,” said Nija Guider in an interview with Tyisha Fernandes of Atlanta’s CBS affiliate. Other attendees said police initially had told them to get into the police vans to get warm since it was freezing cold outside — only to keep them there and haul them off to jail.

This is something you might expect in north Georgia. I know Georgia and these parts of it well. I lived in Atlanta for most of my adult life — the actual city. North Georgia likes to consider itself part of Atlanta, but it’s not. One of the reasons is that it’s outside a belt around the city where the dynamics surrounding race suddenly change. That’s not to say that black people don’t face the risk of arrest for marijuana in the immediate Atlanta area; in fact, the two Georgia counties that make up Atlanta and some of its surroundings have some of the most racially disproportionate rates of marijuana arrests in the U.S., according to a 2013 study by the American Civil Liberties Union.

The arrests happened outside a belt around the city where the dynamics surrounding race suddenly change.

I was warned about this radius around Atlanta — where the rules change — when I first moved to the city to attend Morehouse College in 1997. During our first week of orientation at the historically black college, our campus police department and freshman dean had flat-out told us that we should expect to be confronted with blatant racism if we traveled more than 15 miles in any direction from campus. The warning went on: If we traveled more than 30 miles out of Atlanta and got in any type of trouble, it was unlikely they could help us.

Cartersville is a good 45 miles from the city — well past that invisible 30-mile barrier we were warned to never cross. It’s Trump country: The president got 76 percent of the vote there. The KKK distributed newspapers on lawns throughout the city before the election plastered with Donald Trump’s face and his “Make America Great Again” slogan. This past November when a black family put a house under contract in Cartersville, it got vandalized and had the letters “KKK” spray-painted everywhere.

It’s just the type of town where police would round up cars and vans and buses full of young black folks after finding less than an ounce of weed.

This is why so many of us in the criminal justice reform community are advocating for the full legalization of marijuana. These arrests were a gross overreach of the justice system. It is fundamentally absurd that all of these resources have been wasted, and dozens were forced to endure days in jail because a small bag of marijuana was found at a house party.

If that party in Cartersville had been a mostly white fraternity bash or a birthday party dominated by white folks, there’s no way in hell the police would have rolled up and arrested 70 people like this, for a small amount of marijuana that no one claimed.