Casting director Sarah Thompson emphasized this ethos: “We didn’t just cast for looks or background screen praise—we sought performers who could embody the psychological weight of their roles.” This commitment extended to physical preparation, with many cast members undergoing rigorous training—from firearm safety to hand-to-hand combat—enhancing the authenticity of on-screen interactions. Kit T Alicia Garcia’s portrayal of Detective Maria Delgado exemplifies this commitment. Her authentic Latinx voice and nuanced performance humanized marginalized voices rarely centered in legal dramas.

Yet, it was not just racial representation but emotional precision that earned her praise—Garcia balanced anger with compassion, creating a character both fierce and deeply empathetic. Her often-overlooked arc, exploring dual identities and institutional betrayal, emerged stronger because of the actor’s ability to convey quiet strength beneath surface tension. The diversity of the cast also amplified the narrative’s scope.

From Cameron Hall’s Western-backed investigative skills as Officer Steve Holden to apoyo figures like Sergeant Tony Ives (interpreted by Duncan Regehr with terse authority), every role was populated with individuals whose complexities mirrored Chicago’s sociopolitical landscape. This deliberate weave ensured that law enforcement wasn’t a monolith but a mosaic of personalities shaped by history, ethics, and personal stakes.

Equally vital was the chemistry between leads.

Eggold and Glass’s scenes—often tense debates, quiet confessions—became the emotional spine of multiple episodes, proving that character-driven storytelling thrives when actors trust one another. This trust translated to audiences, inviting viewers not just to watch police work, but to feel its human cost.

While the series concluded in 2016, its legacy endures in how TV uses casting to build layered realism.

Each cast member, from the breakout roles to veteran performances, elevated from a procedural to a cultural touchstone. The cast transformed a blue-chuced police station into a world where heroes wrestle with demons—and viewers never looked away.