In 2014, four police pursuits ended in four separate deaths: a 75-year-old Navy veteran, a 42-year-old nursing assistant, a grandmother, and a speeding motorcyclist. All four chases happened within four miles of one another. And all shared one other characteristic: Everyone killed was black.

A first-of-its-kind investigation by USA TODAY revealed that, on average, 90 black people were killed each year in police pursuits and that deadly chases involving black drivers were twice as likely to start over minor offenses or non-violent crimes.

The investigation involved examining federal records for 5,300 fatal pursuits since 1999 — when the government started tracking the races of people killed in car crashes. The news organization also took a closer look at 702 chases in 2013 and 2014, and reviewed thousands of pages of police documents and hours of video of pursuits across the nation.