When Deanna Cook placed a frantic call to 9/11 last August 17th, her attacker — reportedly her ex-husband — could be heard in the background saying “I’m gonna kill you.” But 9 minutes into the call, despite Deanna’s shrieks, no police officer had come. In fact, it took nearly an hour for Dallas police to arrive at her home, after the officers reportedly stopped for water at a local 7-Eleven store on their way to the house.

Now, Cook’s family is taking legal action against the city of Dallas and its police department, which they say treats 9/11 calls from predominantly black neighborhoods differently than calls from affluent or predominantly white neighborhoods. And the Cook family decries what they call a lack of police urgency in cases of domestic violence. The Dallas mayor denies the family’s allegations, but there’s no denying the tragedy of the family’s loss.

Watch Part one of the NBC News Rock Center piece that aired on Friday above. And in Part two, below, Dateline’s Kate Snow talks to the 911 operator accused of a callous response to Deanna’s frantic call.

Part Two: the 911 operator speaks

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