WASHINGTON The Obama administration has joined the fight against the American bail industry, telling a federal appeals court that bail practices that keep poor defendants locked up because they cannot afford to purchase their freedom are unconstitutional.

Bail practices that do not account for indigence result in the unnecessary incarceration of numerous individuals who are presumed innocent, the Justice Department wrote in an amicus brief filed Friday.

The brief marks the first time DOJ has weighed in on the constitutional requirements of bail systems in a federal appeals court.

Bail practices in the United States often leave poor people languishing in jail simply because they cannot afford a certain amount of money to purchase their freedom . Many of the more than 800 jail deaths logged by The Huffington Post between July 2015 and July 2016 involved individuals who were incarcerated after being arrested for minor offenses and who were unable to afford their bail.

DOJ says that many jurisdictions still incarcerate people without taking their financial circumstances into account, and notes that the use of money bail has increased substantially since 1990.

Maurice Walker is at the center of the case at issue. The 54-year-old was arrested by the Calhoun Police Department in Georgia in September 2015 for allegedly being a pedestrian under the influence. Walker, who has limited income and serious mental health issues, was told he would not be released unless he came up with $160, the fixed amount set by bond for someone charged with being a pedestrian under the influence.

Court was held just once a week in Calhoun, and Walker was arrested on a Thursday before Labor Day when there was no court. He remained in jail for six days, and would have been there longer but he was released after lawyers with Equal Justice Under Law and the Southern Center for Human Rights filed a class action lawsuit on his behalf while he was still behind bars.

A lower federal court had ruled earlier this year that any bail or bond scheme that mandates payment of pre-fixed amounts for different offenses to obtain pretrial release, without any consideration of indigence or other factors, violates the Equal Protection Clause.

That ruling is being appealed by the city, and is also opposed by the American Bail Coalition. ABC claims that the plaintiff takes the extreme position that any defendant is entitled to immediate release based on an unverified assertion of indigency, and argues that bail is a Liberty-Promoting Institution As Old As The Republic.

DOJ, which has faced pressure from advocates to get aggressive in cracking down on unconstitutional practices that plague the American justice system, said that fixed bail practices discriminate against people who lack financial means.

From Fridays filing:

Fixed bail schedules that allow for the pretrial release of only those who can pay, without accounting for ability to pay and alternative methods of assuring future appearance, do not provide for such individualized determinations, and therefore unlawfully discriminate based on indigence. Under such bail schemes, arrestees who can afford to pay the fixed bail amount are promptly released whenever they are able to access sufficient funds for payment, even if they are likely to miss their assigned court date or pose a danger to others. Conversely, the use of such schedules effectively denies pretrial release to those who cannot afford to pay the fixed bail amount, even if they pose no flight risk, and even if alternative methods of assuring appearance (such as an unsecured bond or supervised release) could be imposed. Such individuals are unnecessarily kept in jail until their court appearance often for even minor offenses, such as a traffic or ordinance violation, including violations that are not punishable by incarceration.

The Justice Department filing mentions the consent decree that the Civil Rights Division reached with Ferguson, Missouri, to end unconstitutional bail practices found as part of an investigation into the police department and municipal court there. A recent lawsuit filed by ArchCity Defenders targets other municipalities in St. Louis County that have engaged in similar practices.

Alec Karakatsanis, the co-founder of Equal Justice Under Law , told The Huffington Post that having the backing of the Justice Department as well as organizations like the American Bar Association and CATO is an important step in bringing an end to unconstitutional practices.

Hundreds of thousands of human beings are held in American cages every night solely because they are too poor to make a payment, Karakatsanis said. Todays amicus filings of support by a wide range of groups, including the Department of Justice, takes us closer to finally eradicating poverty jailing from American society.

Read the Justice Departments amicus curiae brief here .