On Monday, the U.S. Justice Department announced it has reached an agreement with Shelby County, Tennessee, to make fundamental changes to its policies and practices for handling juveniles in trouble with the law.

When the Justice Department began investigating Shelby County’s juvenile justice system in 2009, outcomes for teenagers were grim by national norms, with significant numbers sent to adult criminal court for even minor offenses. Law enforcement practices were especially harsh for black youth, who were twice as likely as white youth to be detained and more often wound up in adult court. In April, when the Justice Department’s Civil Rights Division’s Special Litigation Section released the investigation findings, they included evidence that police failed to read young people their Miranda rights; youth were often confined for days without required hearings, restrained physically in the facilities, and denied court documents.

The agreement signed Monday is cause for real optimism: it signals that the Justice Department has begun to approach shortcomings in the nation’s juvenile justice systems holistically, rather than zeroing in on individual facilities for their conditions of confinement. Among the stipulations of the lengthy agreement are measures designed to change the practices of the Shelby County juvenile courts and steer young people charged with low-level offense to therapeutic, community-based programs rather than confining them to facilities modeled after adult lockups.

Dealing with the whole system is an approach that juvenile justice experts have recommended for years but has been a long time coming as a federal response to troubled systems. While the passage of the Violent Crime Control and Law Enforcement Act of 1994 empowered the U.S. Justice Department to protect the civil rights of youth involved in the juvenile justice and detention systems by compelling jurisdictions to design and implement system-wide reform, 2012 marked the first instances of the agency using its authority in this way.

Earlier this year, the Civil Rights Division’s Special Litigation Section sued Meridian Mississippi and Lauderdale County, Mississippi for failing to carry out previously mandated reforms to its juvenile justice system as it relates to the county’s zero-tolerance school discipline policy—known as a school-to-prison pipeline.

The Shelby County agreement shows that the Justice Department has again taken up the tools at its disposal to catalyze system-wide juvenile justice reform.