From 2005 to 2013, black people made up 5.84 percent of the state's population, yet comprised 16.66 percent of those arrested. Asian/Pacific Islanders showed a similar disparity at 2.85 percent of the population and nearly 13 percent of arrests. California was 37.07 percent Hispanic over the nine-year time period, and 42.34 percent of those arrested were Hispanic, all according to "Open Justice."

"Over the last year, facts and figures have been thrown around with little or no ability to verify the data," said Rep. Karen Bass, D-Los Angeles. "Accurate data will allow for distinctions to be made between tragic one-time incidents, and disturbing citywide or statewide trends."

But, Bass said, the disparities in the statewide statistics are troubling.

"African-Americans are the most likely to be arrested at any age," she said.

The DOJ recorded 909 arrest-related in-custody deaths between 2005 and 2014. That statistic includes "incidents while the subject was in an officer's physical custody or under restraint (even if not formally under arrest) or killed by use of force," according to the database.

It includes officer-involved shootings, but is likely still undercounted, however, because arrest-stage deaths were not included in 2005, according to the California Attorney General's Office.

Nearly 75 percent of those deaths were at the hands of municipal police, and more than 20 percent of the homicides were by county sheriff's deputies. The California Highway Patrol accounted for most of the remaining 5.1 percent, with small slivers attributed to state prison corrections officers and other agencies.

Hispanics made up the largest ethnicity killed by law enforcement, at 43.5 percent, or 395 people killed. Black people made up more than 20 percent, with 184 deaths. There were 272 white people killed by California law enforcement over the 10-year period, or 29.9 percent of the whole.

"African-Americans are 3.5 times more likely to die in the process of arrest," said UC Berkeley public policy professor Steven Raphael, who worked on the data sets before they were released Wednesday.

But, he said, there is less of a difference when the data are adjusted for higher arrest rates of black people.

"It already focuses attention on, well, why is there that racial disparity in arrests?" he said.

On the other side of the badge, the data portal reports 345 California law enforcement officers killed in the line of duty between 1980 and 2014, with 187 killed "as a direct result of a criminal act by a suspect" and 158 accidental deaths.

"There have been 280,000 assaults against law enforcement officers in California since 1980," Harris said. "I'll do the math for you: 8,000 assaults a year, and 30 percent of those result in injury."

Los Angeles Police Chief Charlie Beck said it's difficult for local law enforcement agencies to use the local data they collect without the context of statewide numbers.

"Even better, I would like to have comparative data nationally," he said. "I have a lot of statewide data because California is good about reporting. National data -- huge gap, huge gap."

The number of law enforcement officers killed and assaulted is well tracked by the FBI's Uniform Crime Reporting Program, which is where the state got statistics for that data set. Nationwide tracking of arrests and in-custody deaths, however, is far less reliable, despite recent legislation aimed at improving tracking of officer-involved shootings.

Beck, Harris and Bass said they hope California's initiative will be replicated nationwide.