Hailey had a run-in with Trudy Platt when she accidentally spilled coffee all over her. Trudy was very unimpressed, but this changed when Hailey saw her name. She asked if she'd worked in Homicide, and Trudy said she did.
Hailey told Trudy that when she was in her early teens, Trudy helped her and her father after a robbery. She said that Trudy was the reason she became an officer.
Hailey was shown to be slightly impulsive when making decisions, which was shown because she didn't stop to plan when she suggested many of the plans. This could be because she worked in a different unit.
Hailey had a clash with Voight after his unit was called to a bank robbery, but Hailey's unit, Theft and Homicide, had been working on the case for longer. Voight said it was murder but Hailey claimed that she had been tracking the group of robbers for longer.
After some hassle, the two were told to work together. Hailey was fast in investigating the robberies and Voight was impressed. He told her at the end of Fagin that a spot in Intelligence had opened up (after Kim left) and she was free to take it. She didn't reply.