Hundreds of homicides by law-enforcement agencies between 2007 and 2012 aren't included in records kept by the FBI, the Wall Street Journal reports. An analysis of data from 105 of the largest police agencies found more than 550 police killings during those years were missing from the national tally or, in a few dozen cases, not attributed to the agency involved. It is nearly impossible to determine how many people are killed by the police each year.
Public demands for transparency on such killings have increased since the shooting death of Michael Brown in Ferguson, Mo. Ferguson reported to the FBI one justifiable homicide by police between 1976 and 2012. “When cops are killed, there is a very careful account and there's a national database,” said law Prof. Jeffrey Fagan of Columbia University. “Why not the other side of the ledger?” Three sources of information about deaths caused by police—the FBI numbers, figures from the Centers for Disease Control and data at the Bureau of Justice Statistics—differ from one another widely in any given year or state, said a 2012 report by David Klinger, a criminologist with the University of Missouri-St. Louis and a former police officer.