The U.S. Department of Justice has two offices that compile statistics about criminal matters. But it doesn’t keep track of some things that might cast a bad light on the justice system.

For starters, despite recent high-profile police killings of unarmed civilians, there are no official numbers on how often this happens. That question has been left to outsiders, such as The Washington Post, which found nearly 400 people—armed and unarmed—have been killed by police officers so far this year.

“It’s ridiculous that I can’t tell you how many people were shot by the police last week, last month, last year,” Federal Bureau of Investigation Director James Comey said in February.

Justice statisticians also don’t know how many prisoners are locked away in solitary confinement. “There are estimates, but no official count nationwide,” Bruce Western, a professor of sociology at Harvard University, told The Atlantic.

The Vera Institute for Justice says the figure might be 80,000 inmates at any one time.

“But precise statistics remain elusive despite the substantial policy implications,” The Atlantic’s Matt Ford wrote. “There is abundant evidence that prolonged isolation can be mentally and psychologically traumatic. Justice Anthony Kennedy told Congress in April that solitary confinement ‘literally drives men mad.’”

Ford also noted that the Justice Department can’t say how many non-sexual assaults occur in the prison system. “We have anecdotal evidence and some data in individual states that violence is rising in prisons, but we don’t have good, national database collection on that,” Marie Gottschalk, a professor of political science at the University of Pennsylvania, told Ford.

Prisons are required to report numbers on sexual assaults behind their walls thanks to the 2003 Prison Rape Elimination Act (pdf).

-Noel Brinkerhoff

To Learn More:

The Missing Statistics of Criminal Justice (by Matt Ford, The Atlantic)

How Many People are Killed by Police? Crowdsourcing Identifies the Officer-Involved Killings Government Doesn’t Count (by Ken Broder, AllGov)

The Dangerous Overuse of Solitary Confinement in the United States (American Civil Liberties Union) (pdf)

How Many People are Killed by Police in U.S.? Who Knows? (by Steve Straehley, AllGov)