How white engineers built racist code – and why it's dangerous for black people

As facial recognition tools play a bigger role in fighting crime, inbuilt racial biases raise troubling questions about the systems that create them

"You good?" a man asked two narcotics detectives late in the summer of 2015.

The detectives had just finished an undercover drug deal in Brentwood, a predominately black neighborhood in Jacksonville, Florida, that is among the poorest in the country, when the man unexpectedly approached them. One of the detectives responded that he was looking for $50 worth of "hard"- slang for crack cocaine. The man disappeared into a nearby apartment and came back out to fulfill the detective's request, swapping the drugs for money.