(DETROIT) — Sonja Bonnett and her family built their lives in a home a few blocks south of Eight Mile in northeastern Detroit. The family spent years dreaming of owning the property, but then a letter arrived that quickly tore that life apart.

“One day, I get a letter in the mail that says there’s a $5,000 tax debt,” said Bonnett.

In 2011, Bonnett and her family entered a contract to become full owners and made monthly payments that they thought were covering property tax. The Bonnett family soon discovered multiple years of unpaid property taxes.

Bonnett and her husband could not afford to pay those back taxes and, in 2017, the couple, along with their seven children, were forced out of their home.

“The trauma of losing the house, and the way I lost it, killed a lot of how I felt about the neighborhood and the house,” said Bonnett. “But I still care about the people.”

City records showed that the unpaid taxes owed on Bonnett’s home from 2012 and 2013 added up to less than $5,000. A 2020 investigation by the Detroit News estimated Detroit residents, like the Bonnetts, were overtaxed by $600 million from 2010 to 2016.

Based on estimates by the Detroit News investigation, Bonnett’s former home was overtaxed by more than $1,500 in 2012 and 2013.

For years the city of Detroit greatly over-assessed the value of Bonnett’s home and many others like it. From 2011 to 2015, one in four Detroit homes went into foreclosure because of failure to pay property tax, according to a 2018 study.

Alvin Horhn is the deputy CFO and assessor for the city of Detroit. According to city records, the assessed value of the Bonnetts’ home in 2011 was $22,838, but when the property was reassessed in 2017 – it fell to $10,4000 – less than half of what it was valued before.

“There is no question the city lost control of its assessment roll,” said Horhn.

At the time, Horhn said that the city didn’t have the resources for a citywide reappraisal. In 2013, the city filed for bankruptcy and reportedly $18 billion in debt.

“There’s 400,000 properties in the city of Detroit, over 200,000 houses. I would never tell anyone that every single one of them is valued correctly, but that’s why we have a review,” said Horhn.

According to Michigan’s state constitution, property cannot be assessed at more than 50% of its marketable value.

Bernadette Atuahene is a property law scholar who works with the Coalition for Property Tax Justice and is fighting to end over-assessments in Detroit and to get compensation for affected residents. She said her research found that 53% to 84% of Detroit homes were assessed in violation of that rule from 2009 to 2015.

“We find that the burden of these illegally inflated property taxes is being borne on the most vulnerable homeowners, the ones in the lowest valued homes,” said Atuahene.

While Detroit acknowledges the over-assessment problems in past years, the city told ABC News that the problem is no longer happening.

“There are no systemic over-assessments in this city. If I were to tell you that 95% of the assessment roll is correct, that’s still 5% [or] 20,000 houses that could possibly be overvalued,” said Horhn.

But Atuahene and other housing advocates would argue otherwise. A 2020 study from the University of Chicago found that while fewer Detroit homes were being assessed in violation of the constitution, the city’s lower-valued homes were still being over-assessed.

The problem is not unique to Detroit. A 2021 study found that property rates are 10%-13% higher for Black and Hispanic residents nationwide. In recent years, investigative reports have uncovered disproportionate assessments in Cook County, Illinois, and Philadelphia.

“Detroit is just ground zero for a national problem. We see these inflated property taxes. It’s a national racial justice issue that our country has yet to come to tackle with,” Atuahene said.

In 2020, Detroit proposed a plan offering benefits for homeowners affected between 2010 and 2013, including discounts for properties owned by the Detroit Land Bank, authority and priority access to affordable housing and city jobs. The plan was voted down by Detroit’s city council, with critics saying it didn’t go far enough.

“The city does not have the money to hand people cash. It’s against state law and the city is not going to do anything that could bring the FRC back in control of their finances,” said Horhn.

Residents like the Bonnetts said if the city can admit it was wrong, they have the obligation to make it right.

“I want the world to take a look at what’s going on here… When you talk to Detroiters who went through this, we want our money back,” she said. “Why am I just accepting whatever they can give me?”

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