What is the name of the DEA agent played by Scoot McNairy in Narcos: Mexico?

The DEA agent played by Scoot McNairy in Narcos: Mexico is Walt Breslin. He becomes the central American law-enforcement viewpoint in the later story, leading Operation Leyenda, the investigation and retaliation following the kidnapping and murder of DEA agent Enrique “Kiki” Camarena.

Breslin is introduced as a narrator near the end of the first season and becomes a major character in seasons 2 and 3. His work brings him into conflict with Miguel Ángel Félix Gallardo and the powerful trafficking organizations that emerge after the Guadalajara Cartel begins to fracture. The show presents him as determined and morally complicated rather than as a straightforward heroic agent.

Walt Breslin is a fictional composite character, loosely based on real DEA personnel, including investigator Héctor Berrellez. That distinction is a common source of confusion: Kiki Camarena was a real DEA agent, while Breslin was created for the series. Javier Peña and Steve Murphy are the principal DEA agents associated with the original Narcos storyline, not McNairy’s character in Narcos: Mexico.