Detective Inspector Kathy Swanson was a police officer in Cardiff.
Kathy investigated a series of murders committed in Cardiff. As the murderer had written the word "Torchwood" in blood, she blamed Torchwood Three as being responsible once they arrived on the scene.
Torchwood captured the murderer, Max Tresilian, but through a series of triggers planted by Suzie Costello, placed the Torchwood Hub in lockdown. Torchwood called Kathy for help and she bought a poetry book by Emily Dickinson. She told them the ISBN which unlocked the Hub. (TV: They Keep Killing Suzie)
Over a year later, Kathy was investigating the murder of students, and was once again irritated by the interference of Jack Harkness. (PROSE: Bay of the Dead)