How does Starr reference the cop that shot Khalil in The Hate U Give?

Starr refers to the cop that shot Khalil as One-Fifteen.
During the stop, Starr reminds herself of her father's advice to remember what the cop looks like and his badge number. In the moment, the first thing Starr notices is the badge number: 115. Next, she assesses the way he looks. He's middle-aged with a buzz cut, white skin, brown hair, and a scar over his top lip. The situation escalates quickly and the cop ends up shooting Khalil, who's unarmed.
For the rest of the book, she refers to him as One-Fifteen or, less often, Officer One-Fifteen. Later, the reader finds out that his name is Brian Cruise Jr. and he's been on the police force for sixteen years. When she finds that out, Starr thinks that One-Fifteen was a cop for as long as Khalil was alive.