X Marks the Murder, Part I: Diagnosis Murder (1996)

Diagnosis Murder was one of my absolute favorite TV shows growing up. It came on every Thursday night on PAX and it was the only time that my parents would let me stay up past my bedtime on a school night.

Dr. Mark Sloane (Dick Van Dyke) is the super intelligent doctor at Community General Hospital in Los Angeles, CA. He always loved mysteries and wanted to be a detective, achieving this dream by helping his police detective son, Steve (played by his real son Barry Van Dyke). The two are rounded out by Dr. Amanda Bentley (Victoria Rowell), the medical examiner; and Jack Stewart (Scott Baio); guy from a crime family turning from that life and making something of himself. Jack ended up leaving to go to Denver, and they brought in the character Jesse Travis (played by Charlie Schlatter), my second favorite character. Jesse is the sweet, handsome, and adorable resident at Community General, and later head of the Emergency Room.

With each episode their would be a case that Steve was on, with him bringing in his dad and subsequently the rest of the team; although sometimes Mark would have suspicions about something and being Steve into it. Either way it was one awesome show that balanced mystery, medicine, and crime.

Mystery, you say?

Which brings us to today’s episode. Now I really struggled choosing just one as I have so many favorite episodes, in fact I originally wanted to review one last year but couldn’t decide so I shelved it until this year. After a lot of deliberating and going back and forth I finally settled on this two parter.

This episode is the fourth episode in season four. So far this season we have had a cop kill his partner “accidentally” only for it to turn out to be the widow who had been pulling the strings; the staff at Community General had to battle a smallpox strain, and outsmart a Tonya Harding-like killer.

This episode has special guest star, John Schneider (from the Dukes of Hazard), as a serial killer obsessed with Mark Sloan. We start the episode off with him preparing ritual: lighting candles, dressing the victim in lingerie, everything looking romantic-and calling Dr. Sloan to battle him. I can’t remember if this is the first time, but it most definitely will not be the last time a killer/criminal decides they want to go head to head with Dr. Sloan. He just attracts all the crazies.

Steve has been appointed in charge of the task force to discover the identity of the serial killer. Of course they hope that if Steve is in charge they can assist in the solving of the case.

There is a “B story” about Norman the hospital administrator, but is really boring and not really my time reviewing.

Steve heads to the latest victim of the “Casanova Killer” and finds everything to be the same as the prior three cases, even down to the Xs cut into the feet and no sexual contact. Also coming there is medical examiner, Dr. Albert Blank, played by Kurt Fuller. Yes you may recognize him as coroner Woody Strode in Psych. To be honest the way he acts, it is basically the same character although instead of silly/sweet/creepy/awkward he’s just creepy/awkward.

Back at the house Steve asks Mark to join him as he needs the best on his side. He, Mark, and Amanda start discussing the case. They share the info that has not been shared to the public, along with the fact that the victim had called Community General the night she passed, but there isn’t any record of her calling and someone talking to her.


When our Serial Killer finds out Mark is on the case, he is ecstatic-that’s exactly what he wants.

Later Mark and Albert meet up to discuss the case. Albert is super awkward, but a little upset that Mark no longer works with him, picking Amanda over him. Mark senses the disgruntlement and tries to smooth things over. Albert reveals that he has no money and his marriage is kaput. His wife sounds exactly like the wife of Woody in Psych. I think the Psych writers just copied the character but made him warmer.

Defense attorney Andrew King approaches them and tries to snoop for info. He really lays on the flattery for Albert which makes me very suspicious. I totally believe Albert would turn over information for more compliments.

Mark goes over the notes but finds them hard to unravel. He decides to give them to Amanda and have her take a second look. While at home perusing the case files he gets a call from the killer who is more than eager to share how pleased he is to have Dr. Sloan’s attention. This dude is extra crazy. I mean we already knew he was out of his mind as he’s a serial murderer, but his level of obsession with Dr. Sloan makes him double the crazy.

You are crazy

We see our serial killer working at the gas station, ouch the prices on this gas makes me hurt as they are sooooo cheap. I wish I could pay that today in California as currently has I like 5.69 a gallon.

I digress, he works at a gas station/car repair/car detail shop. It appears that as he’s handsome it’s easy for him to charm the women and make them feel comfortable. When patrons pay with a credit card he uses the excuse of needing to see ID (remember when you had to do that with every purchase?), to write down the personal info and select his victims.

Amanda comes to get gas and forgot her purse. The attendant/serial killer is intrigued when he hears that Amanda is a friend of Mark’s. Uh oh.

Later Amanda does another examination of the recent murder and discovers a fiber in the eyelash of the victim. Very interesting, and hopefully a clue to track down the killer.

Jesse is looking into the past crimes that Mark has solved while Amanda tracked down the recent credit card purchase to see if the victims intersected. No dice.

Unbeknownst to then, our killer is watching them and calls Mark taunting him. Steve tries to track the call, but our killer is too smart for them and has been calling from a pay phone. Our killer is angry that Mark hasn’t made more of an effort to find him and decides to up the ante. Oh…not good.

Our killer goes hunting for his next victim, finally letting us know his name is Michael Dern. He does increase it, killing two women in one night.

The next day they discover that the fiber on the eyelash was cotton soaked in baby oil. It appears either the women are taking their make up off, or he does it. Either way this case has gotten creepier.

SUPER creeped

Mark heads to get gas for his car and it turns out that he goes to the station Michael our serial killer works out. The two are friends it be way you have your favorite checker and we see why Michael is so obsessed as he feels Mark ignores his intelligence and looks down on him/slash he appears to be the only one who can match him in “smarts”. He gives Mark a car cover, recommending it as someone he uses; an obvious clue to the viewer-he’s trying to help Mark find him.

Steve gets to the cases and is upset that there are two, while Albert is just his usually weird self. Later that evening Albert meets with Amanda to give her the info, and it seems like defense attorney Andrew and Dr. Albert are no longer friends. Interesting…hmm.


Amanda brings the notes to Mark’s house where they go over the autopsy report and discover that all the six victims seem to be the same but they do not appear to intersect with each other-except the first five did go to the same gas stations; victim six is an outlier. But it can’t be a copycat right? None of the info was shared with anyone except those few on the case.

Meanwhile, Amanda visits the gas station Michael works at again, and this time uses her credit card. Michael takes down the info along with her vanity plate, Dr. AL (AL for Amanda [Bentley]Livingston, Amanda was married for a brief while).

You’re next! You’re next, You’re next…!

That evening Steve and Mark are trying to figure out why a woman would allow a stranger into their house when they get the idea of a serviceman of repairman being behind it. Just as they come to that realization, they receive another call from Michael who threatens to kill Dr. Al; Michael means Amanda while Mark thinks he is referring to Dr. Al Blank. Mark is confused, but insults Michael in order to keep him on the line and trade where he calls from.

Amanda is home alone as her husband and son are out of town for a little while when Michael comes knocking by claiming to have her credit card. However, unlike the other women she doesn’t let him in but checks her purse and intends to call the police, stopped by Michael who snuck into the house.

They track the call to the gas/service station where they find out Michael is the one behind it all. While there Mark discovers that Michael set up a system where every car being repaired or detailed on is referred to by their license plate. Good thing too a they are able to save Amanda instead of wasting their time going to Dr. Albert’s.

While prepping his ritual Michael complains to Amanda about how Mark never pays attention to him. He sounds like those girls/guys who believe they like someone (when they really didn’t) and get all weird/angry when the person doesn’t like them back.

Amanda tries to prolong him and we end up discovering that he hates women because of his abusive mother who tortured him. It turns out she died six months ago, and that is exactly what started the killing-his trigger.

All are celebrating over their arrest of Michael when their receive a call he wants to talk to Mark. Mark reluctantly goes down there and hears Michael talk about his victims. He also shares a really important tidbit, that he did not kill the sixth victim. That’s why she doesn’t match the others with the overlap of the gas station. Uh oh, that means not only do they have a copycat it has to be someone who was involved in the case as the murder was identical to the others. At best one of the people on the task force is a mole/shared the information with someone.

But the worst and far more likely, one of the members of the task force is a killer.

Before they could question Michael more, he’s murdered. They try to speak to the guy’s sharing the cell with him, one has disappeared as he made bail without making a call. Very suspicious but the case is “over” as everyone wants to believe Michael did it and it’s case closed.

Steve doesn’t like this and puts himself on the case of finding Michael’s murderer. He discovers that the guy who killed Michael is also dead. It is clear that Micheal didn’t kill the 6th victim. But if it wasn’t Michael who killed her, and tried to frame him?


For more mysteries, go to The One Thing About A Murder Case Is- If You Just Let People Talk Long Enough, Sooner Or Later, Somebody Will Spill the Beans.: Shadow of the Thin Man (1941)

For more mystery TV shows, go to Murder in High C: Murder She Wrote (1995)

For more serial killers, go to What If the Man You Married Wasn’t Who You Thought He Was?: Flower of Evil (2020)

For more Kurt Fuller, go to Is Lassiter Crazy or Has He Discovered a Criminal Case in a Recovery Hospital?: Psych 2, Lassie Come Home (2020)