Illegal dumping is a problem in parks, vacant lots, alleys, all over Washington. You may have seen a tire or two in your local creek. But 1,000-plus tires?

“This is one of the largest tire dumps I’ve ever seen,” says Tommy Wells, director of the District Department of Energy and Environment. “This is just a major crime.”

The tires were dumped in Southeast D.C., on a forested hillside behind a row of apartments on land owned by the National Park Service, part of the Fort Circle Parks. D.C. police have spent weeks trying to figure out who did it. On Thursday, police announced they had a suspect: 56-year-old Deron McDonald, of Alexandria, Virginia.

D.C. police, DOEE employees, and volunteers with the Anacostia Watershed Society spent the morning removing the tires.

“It was like a fire line almost,” says volunteer Deb Jackson. “We just did a line of people and just rolled the tires out and down this hill and to stack them up in the dumpster. When the dumpster got filled, they just stacked them up in the grass.”

Jackson is furloughed federal employee who works for the Department of Agriculture. Her clothes were covered with mud and tire gunk. The weather was freezing and windy. But she was having fun.

“This was good to do,” she says. “Otherwise I’d be sitting at home cleaning my house.”

Julie Lawson, director of the mayor’s office of the clean city, says she first heard of the tire mountain in December, when she got a phone call from an officer on the environmental crimes unit of the D.C. police department. “He said we found, what he called ‘a metric crap-ton of tires’ behind an apartment building in Ward 7.”

As volunteers continued to roll tires down the hill, Lawson eyed the growing stacks of them. “We obviously misjudged the size of the dumpster we would need to remove them,” she says.

Cases like this can be tricky to crack, and often investigative resources are deployed elsewhere — like tackling the city’s rising homicide rate. DOEE Director Tommy Wells credits success in this case to a program called Dumpbusters, a partnership between the environment and public works departments and the police. “We’re enforcing environmental crimes,” says Wells. “We pay for the cameras and MPD watches them. We’ve caught over 139 folks, and each one pleads guilty because we have them on camera.”

D.C. Police Chief Peter Newsham says tips from neighbors also helped solve the case (after all, this bit of park land backs right up against a large apartment building and a row of townhouses — lots of windows looking out over the crime scene). Newsham says the suspect used a stolen vehicle to dump the tires here on the afternoon of November 6, 2018.

“Someone at the end of the day is cutting corners. Someone who’s trying to get rid of trash will use an unlicensed hauler to do it, and this is the result. You have a thousand tires in someone’s community,” says Newsham.

Newsham declined to say what sort of punishment the suspect may receive, if convicted. “Hopefully the consequences will be suited to the crime,” he said. Under D.C. law, illegal dumping is typically a misdemeanor punishable by a $5,000 fine for the first offence and $10,000 for each additional offence, and up to 90 days in prison. However, if the waste is dumped “for a commercial purpose,” it’s a felony, subject of a fine up to $40,000 and five years in prison.

Police have yet to apprehend McDonald. They’re asking for the public’s help finding him.

As for the tires, they will be collected and taken to be recycled.

This story originally appeared on WAMU.