Inspektor Lestrade is a detective from Scotland Yard who appears as a major character in the first story arc of Lupin the 3rd Part 6. His outward appearance is that of a calm and trustworthy officer, with gray hair, black eyes, and a consistent professional wardrobe consisting of a gray suit, a red tie, and black shoes. In his public-facing role, he is a respected investigator known for collaborating with the famous detective Sherlock Holmes, and he upholds an image of reliability and kindness. This is particularly evident in his relationship with Lily Watson, the young daughter of the late Dr. John H. Watson; Lestrade had known Lily since she was very small and acted as a sort of uncle figure to her, showing her consistent guardianship and warmth. Professionally, he works alongside Holmes, projecting a demeanor of being a calm and helpful colleague.

However, this benevolent facade conceals a much darker truth. Lestrade is secretly a member of the Raven, a powerful and shadowy organization that manipulates the British government from behind the scenes. It is eventually revealed that a decade before the main events of the series, he was the one who murdered Dr. John H. Watson, Holmes's partner and Lily's father. The murder was witnessed by a young Lily, who was wearing a distinctive yellow scarf at the time. In an attempt to cover his tracks, Lestrade removed the scarf from the crime scene, a seemingly small detail that would later be used by Sherlock Holmes to identify him as the killer. His motivations are tied to his allegiance to the Raven, and his actions reveal him to be a ruthless conspirator willing to commit murder to serve the organization's goals, which also involved targeting multiple other individuals.

Lestrade's role in the story is that of a hidden antagonist and the central figure behind the mystery of Watson's death. He serves as a foil to both the gentleman thief Lupin III and the detective Holmes. His downfall begins when his guilt is exposed during the investigation into the treasure of the Raven. The climax of his arc occurs on London Bridge, where he is pursued by both Lupin III and Sherlock Holmes. Cornered and with his true nature revealed, Lestrade makes a final request to Holmes, asking him to deliver a message to Lily. He then falls from the bridge into the river below and immediately detonates an explosive device, killing himself in the blast. In his final moments, Holmes, who had once trusted him as a colleague, calls him a fool. The tragedy of Lestrade's character lies in the sharp contrast between his benevolent public persona as a kind inspector and uncle to Lily and his concealed identity as a cold-blooded murderer and conspirator. Regarding notable abilities, his primary skill is his capability as an investigator for Scotland Yard, which he uses to maintain his cover while secretly working against those he is sworn to protect.