Dr. Mark Sloan is having himself a couple of problems. One is a young boy whose mother he can't seem to get a hold of, and another is one of his patients, Nick Osborne. Osborne himself has a problem in the form of his boss Russell Cord, head of the Cord Media group. As it happens, Cord is selling off his business, which threatens Nick.
And as it turns out, Cord has three problems of his own. Those problems being his head of film production Frank Stevens, his head of his book publishing Anita Clifford, and the head of his TV productions Eric Walker. In that sale of their departments, he'll leaving them with a generous share of nothing. So bad are things that in the night, a person in black makes their way into Russell's office and strangles him to death, framing Nick for the crime on the way out.
Dr. Sloan knows Nick too well to think of him as a murderer, so he takes recruits fellow doctor Jack Parker and Community General pathologist Amanda Bentley to discover the truth.
"Diagnosis of Murder" displays symptoms of the following tropes:
- And Starring: Bill Bixby as Nick Osborne.
- Artistic License – Medicine: Mark is shown teaching his students about the term "iatrogenic", meaning a condition induced by a doctor. The definition is correct, but what isn't is describing it saying "genic" as "doctor" and "iatro" as induced. He is mixing up the prefix and suffix.
- Bait-and-Switch: When Anita is found switching the labels on the blood vials, the viewer naturally thinks she is the killer. As it turns out, she was switching the labels on Eric's orders.
- Bluffing the Murderer: Mark proclaims that the steroid Russell was using at the time and jabbed his killer with is likely still in his killer's bloodstream. Thus he has samples taken of all three and plans to test them in Community General's lab. Of course, what he really wants is to find which of the three comes by to tamper with the vials.
- Early-Installment Weirdness: As this is the first time at the show, some details are rather off:
- Amanda is a White woman played by Cynthia Gibb instead of a Black woman played by Victoria Rowell.
- Jack is played by Stephen Caffrey instead of Scott Baio and his surname is "Parker" instead of "Stewart".
- Steve is a sergeant rather than a lieutenant.
- Car Fu: As Nick chases the killer into the parking garage, they hit him non-fatally with their SUV and take off.
- Fire Alarm Distraction: Anita pulls the fire alarm at Community General in order to evacuate it and get access to the blood vials.
- Frame-Up: The killer leaves the belt they used to strangle Russell to death by Nick as they drive away. As stated below, they also try to frame Frank Stevens.
- No Honor Among Thieves: Eric tries to frame Frank for the murder by having Anita switch the labels on the vials and was perfectly willing to throw her to the wolves if she got caught.
- Stealing from the Till: Frank, Anita, and Eric were pulling an elaborate one with the Cord group's money. They created a fake company known as Phoenix, paid them company money for "research", and pocketed the cash.
