This character is best known for her pure sex appeal, specifically her large breasts, which provided the series with countless sight gags, and penchant for wearing tight fitting clothing. A more serious version of Tackleberry, Debbie Callahan is portrayed as a stoic, no-nonsense officer who is both physically and sexually aggressive. She along with Harris trained the cadets in the first film, but she does not show the outright hostility towards the cadets that Harris does.
In her role as a teacher to the cadets, she usually gets into situations where after explaining or demonstrating the lesson, she is usually flanked by the male cadets volunteering to be her next test-subject. For example, in the first movie, where she demonstrates self-defence: Leslie Barbara is her test subject, whom she swiftly takes down and sits on his face. When she asks for volunteers, all the male cadets promptly and eagerly volunteer. Another example is in the fourth movie, she teaches a lesson about saving drowning victims, in which she plays the drowning victim: After she dives in the pool, swims to the middle, and surfaces with her white T-shirt hugging tight to her body, she asks, "Now, who is going to save me?" Immediately, all the male cadets jump into the pool and swim after her, while she frantically tries to get away.
She is an avid weightlifter and also knows martial arts and has a good singing voice. In the first film, she has a relationship with Cadet Martin; in the third and fourth film, she has a relationship with Japanese foreign-exchange cadet, Nogata. She is seen partnered with Tackleberry in the 4th and the 5th films, (keeping him and his gun obsession in line), and in the animated series. She appears in every film except the second, and is promoted to Lieutenant and then Captain.
In the Police Academy: The Series episode "Dead Man Talking", Callahan has retired from the Police Force and has been elected District Attorney.
Her name is a reference to Harry Callahan, the star of the Dirty Harry series of films, as well as Debbie Harry.