In a beach house, teenager Ashley York helps out with care for her ill father Arthur. On this night, she has had a little too much of his bad behavior, and thus she swaps out his daily medicine for a lethal does of his diprosene pills. Mark soon has a funny feeling that Arthur's suicide was not so.
Meanwhile, a whole batch of changes between seasons 2 and 3 rear their heads. Jack is no longer a resident of Community General. In his place is young resident Dr. Jesse Travis, who is no less eager to jump into solving the mysterious death. Amanda is not only married to a soldier. but is now expecting a baby. Mark and Steve now live together on a beach house, one close by to Arthur's in fact. Delores is nowhere in sight, and Norman... well, he's actually still Norman.
Plenty may have changed on this show, but one thing sure has stayed the same. Diagnosis in the death of Arthur York: Murder.
"An Innocent Murder" displays symptoms of the following tropes:
- Abomination Accusation Attack: When Mark confronts Ashley in the locker room at her high school, he accidentally rips the sleeve off her shirt while she is walking away, even leaving scratch marks. She threatens to report him for sexual assault if he doesn't drop the investigation.
- Absence of Evidence: Part of what draws Mark's suspicions in the case is that both the pill bottle Arthur supposedly used in his suicide along with the glass of water he used to help take the pills have no fingerprints on them, not even his own.
- Addled Addict: Dr. Elaine York has a nasty phenobarbital addiction, and has had it for the last 15 years. She apparently had it under control for a while, but the death of her youngest daughter Rebecca sent her into a tailspin and exacerbated the addiction.
- Blackmail:
- Arthur had been blackmailing Elaine to pay his rent, as well as leaving him most of the money when they got devorced.
- Ashley blackmails both her swimming coatch (to have an affair with her) and Mark (to drop the investigation about her father's murderer).
- Bluffing the Murderer: Jesse chats up Ashley in the Community General lobby, saying Mark has found out that Arthur's murderer dropped one of the diprosene pills, and the pill will have their fingerprints on it. Ashley sneaks into Arthur's house, finds the pill in the kitchen, and puts it down the drain. However, Mark says the pill she just destroyed was a decoy Mark put out for her. Arthur's maid vacuumed up the original pill before she found Arthur's body, which Mark now has bagged.
- Chuck Cunningham Syndrome: While we get an explanation for Jack leaving the show, we do not get one for Delores.
- Death of a Child: Rebecca, Ashley's little sister, had died years ago.
- Failure-to-Save Murder: Arthur blamed Ashley for not saving her little sister, Rebecca.
- Fille Fatale: Ashley has once seduced her swim coach into sleeping with her, and blackmails him with a rape accusation to keep him doing it. Yeesh.
- I'm a Doctor, Not a Placeholder: When Mark asks around who made the coffee, one of the people answers "I'm a cop, not a waitress".
- Let Off by the Detective: Mark doesn't report Ashley's swim coach for sleeping with her, as the times after the first one have been under blackmail.
- Medication Tampering: Ashley killed her father by replacing his normal evening medicines with an overdose of diprosene.
- Never Suicide: Dispite first impressions, Arthur did not commit suicide. He was murdered.
- Outliving One's Offspring: Arthur and Elaine had an other daughter, who had died years earlier: Rebecca.
- Put on a Bus: Jack is revealed to have left Community General after his residency, and has now set up his own private practice in Colorado.
- Self-Made Orphan: Arthur is murdered by his daughter Ashley.
