Amy Bach was researching her book about the US court system when she met a woman named Sharon in Quitman County, Mississippi. One July day in 2001, Sharon said, her boyfriend took her under a bridge and beat her senseless with a tire iron. Sharon passed out numerous times before her niece intervened and stopped the man from killing her. In photos from the emergency room after the attack, Sharon's brown, almond-shaped eyes are swollen shut. She reported the crime to the police, who wrote up an aggravated assault report.

And then nothing happened. Neither the police nor the local prosecutors pursued the case. As Bach's research later revealed, Quitman County hadn't prosecuted a domestic violence case in 21 years. When Bach brought her discovery to the prosecutor, she remembers him saying, "Has it been that long?"

Quitman County, the fifth poorest in Mississippi, had next to no readily available data about how its own court system operates, who it affects, or who it leaves behind. As a criminal justice writer and attorney, Bach knew that wasn't an unusual scenario. But that didn't make it any less of a problem.

"He didn't even see it," Bach says of the prosecutor. "You can't change what you can't see."

Compelled by the experiences of Sharon and so many others collected in her 2009 book Ordinary Injustice, Bach set off on a multi-year, labor-intensive effort to build a free, public tool that would make the many injustices in the court system a little bit tougher to ignore. Measures for Justice launches today with deep data dives on more than 300 county court systems in Washington, Utah, Wisconsin, Pennsylvania, North Carolina, and Florida, with plans to expand to 20 states by 2020. It pulls together the data that has traditionally remained hidden in ancient databases and endless Excel spreadsheets.

Even with just six states included, the comprehensiveness of the platform surpasses anything similar that currently exists. Measures for Justice compiles granular data for 32 different metrics that indicate how equitable a given county's justice system might be. The portal shows, for instance, how many people within a county plead guilty without a lawyer present, how many non-violent misdemeanor offenders the courts sentence to jail time, and how many people are in jail because they failed to pay bail of less than $500. It offers insight into re-conviction rates and never-prosecuted cases. Users can compare counties or filter information based on how certain measures impact people of different races or income levels. And the site organizes all of it into easily digestible data visualizations.

Bach's work has attracted the attention of the tech industry's increasingly activist leadership. Earlier this year, Google.org awarded Measures for Justice a $1.5 million grant. Today, Mark Zuckerberg's Chan Zuckerberg Initiative announced it is giving $6.5 million to the non-profit to help it expand into California.

"Better access to criminal justice data is important for informing efforts to make our communities safer and our criminal justice system fairer," said Democratic strategist David Plouffe, who now serves as the Chan Zuckerberg Initiative's president of policy and advocacy, in a statement. "You can’t solve a problem if you don't have the facts."

Some counties had their own databases to hand over to the Measures for Justice team. Most did not. That meant researchers often had to travel from county to county requesting individual records from local government agencies. The team then used automated character recognition tools to process the information into one central repository. "The data is like a snowflake," says Andrew Branch, director of technology for Measures for Justice. "Every county is different."

That process, Bach says, illustrates just how fragmented the American justice system is. More than 188,000 people are incarcerated in federal prisons, while roughly 2 million are locked up in state prisons and local jails. As Bach says, "Justice in America happens in 3,000 counties, each with its own justice system."

For criminal justice reform advocates concerned over the newly aggressive Justice Department attitude toward maximum sentences and broad crackdowns, the fact that cities and states enjoy this autonomy can be comforting. Communities can set their own priorities and goals. But overworked and understaffed district attorneys' offices can make only so much progress if they don't know what's happening in their counties.

When residents of Winnebago County, Wisconsin, elected Christian Gossett district attorney in 2006, he inherited a backlog of nearly 900 cases that the 10 attorneys on staff had never prosecuted. Gossett got to work making the department more efficient, cleared the backlog, and set up diversion programs that could keep low-level offenders out of jail. He was feeling proud of the advances his office had made.

Then he began working with the Measures for Justice team. After digging into the data, they found that among people with no previous records who had committed non-violent misdemeanors, white defendants were nearly twice as likely as non-whites to enter diversion programs instead of going to jail.

"I never would have guessed it," Gossett says of the discovery, "but it’s there, and I'd rather know it so I can fix it."

As it turns out, Gossett found judges were offering white and non-white defendants the option to enter diversion programs such as drug rehabilitation at equal rates. But non-white defendants opted for jail time more often. And choosing jail means opting for a criminal record, which can mean opting for a life in which everything from jobs to loans become much tougher to get. Now Gossett is working to get to the heart of why people are making this decision. Maybe it's because they can't afford the transportation to the diversion facility, or perhaps it's because of a lack of trust between minority communities and law enforcement. Now Gossett says he's at least a little closer to figuring out the answer. "We wouldn't have known to look for that, because we didn't know it was an issue," he says.

For all of the valuable information Measures for Justice has collected, it's far from complete. It does not, for instance, include any information on police behavior or anything that occurs before an arrest takes place. A broader swath of such information could come in time, according to the Measures for Justice team. For now, Bach and her staff are focused on filling a vast information void in hopes of creating a justice system that lives up to its name.