NCIS carved out its unique identity in the world of procedural dramas, setting itself apart from its predecessor, JAG. According to executive producer Donald Bellisario, the key difference between the two shows lies in the shift from military law to investigative work. While JAG focused primarily on the courtroom and military legal proceedings, NCIS embraced a more dynamic and action-packed approach, blending criminal investigations with personal dynamics among its team members. This focus on teamwork and engaging character arcs allowed NCIS to resonate with a broader audience, beyond just military fans.

Bellisario also noted that NCIS took a more contemporary and relatable approach to storytelling by exploring the emotional and personal aspects of its characters, which helped humanize them. Unlike JAG, which often featured more formal, procedural storytelling, NCIS delved into the complexities of relationships and personal stakes. This shift in tone and approach made NCIS not only a procedural hit but also a long-running favorite, as it built a loyal fan base over the years by combining high-stakes action with character-driven plots.