'Scarpetta' Ending, Explained: Breaking Down Who the Killer Is in Both Timelines

After solving cases in 29 books spanning more than three decades, Dr. Kay Scarpetta, the heroine of Patricia Cornwell’s series of page-turning crime novels, finally received her own thriller series adaptation.

In the Prime Video show, Scarpetta, Nicole Kidman stars as Kay, the chief medical examiner for the Commonwealth of Virginia, who uses forensic techniques and her brilliant mind to track down killers and get justice for victims. Season 1 of the murder-mystery unfolds across two timelines, taking inspiration from two of Cornwell’s books: 1990’s Postmortem, and 2021’s Autopsy.

How these two stories connect, and the big cliffhanger it leads to, is all part of the mystery Kay has to contend with—both in the past (in which Rosy McEwen plays her) and present. Read on for a breakdown of the Scarpetta season 1 ending.

Who killed Gwen Hainey and Cammie Ramada in 'Scarpetta?'

Kay—with the help of her longtime investigative partner (and now brother-in-law) Pete Marino (Bobby Cannavale and Jake Cannavale in the present and past, respectively)–was able to connect the murders of Gwen Hainey (Emma Massalone) and Cammie Ramada (Brittany Belt) to the same killer.

The identity of the perpetrator, however, isn’t revealed until the season finale, and it’s someone Kay has known all along. It was Officer August Ryan (David Hornsby and Austin McMains), a cop she encountered during her investigations dating back to the Lori Petersen case in 1998.

Ryan was one of the first cops on the scene after Lori (Kassia Conway) was killed, and seeing her body unlocked something from his childhood: His uncle was a rapist who brought the young Ryan along while committing his crimes. He was given a penny to try to flatten on nearby train tracks as a distraction, which is how that became his signature to leave behind at his own crime scenes.

The officer became obsessed with Kay and, when she returned to the Virginia medical examiner’s office at the start of the series, began committing murders inspired by the ones she investigated years ago. This is all revealed when Ryan comes to Kay’s home at the end of the series, planning to strangle and kill her next. Thankfully, she’s able to resist and takes him down by beating him mercilessly with a baseball bat.

And who was the killer from the 1998 timeline in 'Scarpetta?'

The 1998 case came down to some good, old-fashioned detective work. Pete initially pegs Lori Petersen’s husband, Matthew Petersen (Graham Phillips and Anson Mount), as the prime suspect, but Kay disagrees: If this were a case of “the husband did it,” why would he also kill the other women in the same gruesome manner?

One breakthrough came via one of the strange coincidences that tied the cases together: a mysterious substance on the bodies that sparkled under a black light. That turned out to be a byproduct of a powdered soap the killer used to wash his hands, which he did frequently to cover up a medical condition (if you were curious, “maple syrup urine disease” is indeed a real thing) that gave him a distinct body odor.

Through tracking down the brand of soap and deducing that the killer chose his victims by the sound of their voice, Kay and Pete conclude that this man must do a job that requires him to be on the phone. That suspicion proves correct: The serial killer is a 911 operator named Roy McCorkle (Martin De Boer), who answered calls made by the victims.

How was Matt Petersen connected to Gwen Hainey in 'Scarpetta?'

One of the big questions hanging over Kay and Pete throughout the present-day investigation is why Matt Petersen’s fingerprints were linked to the Gwen Hainey case. If he were involved, that would mean that they got the wrong guy in the 1998 murders—and the case that made Kay’s entire career was built on a lie.

Turns out, Matt really just was a man grieving his murdered wife, though he winds up taking that in a weird (and potentially unsettling) direction. Now, 30 years on, he’s refashioned himself as a spiritual guru helping people deal with grief on a farm he operates as a kind of commune. He did meet with Gwen, but not to kill her: He’d read articles about her work at a bioengineering firm that was experimenting with 3D-printing synthetic human organs, and chatted with her about it after recognizing her out at a bar. So he had no interest in wanting Gwen dead and lots of reasons to want her alive. (Namely, so he could clone his dead wife. Like we said, unsettling!)

Also, what’s the deal with the whole space plotline in 'Scarpetta?'

And you thought the 3D organs were weird! Thor Laboratories, the firm where Gwen worked, was also conducting experiments on growing human organs in space. One of the astronauts on that orbiter was colluding with Gwen to sell the company’s trade secrets to the Russians, and murdered his colleagues before jumping off the ship onto another vessel. The dead men and the orbiter then crash into some poor man’s farm, making it a very active FBI scene investigated by Kay’s husband, FBI agent Benton Wesley (Simon Baker in the present, Hunter Parrish in 1998), and his partner.

This plotline is a red herring of sorts, because it seems for a moment like Gwen’s death could have been tied to her corporate espionage—but it also reveals that Benton knows more about the Gwen investigation than he’s telling his wife.

Who hacked Kay’s computer in 'Scarpetta?'

In both the past and present, Kay faces harsh professional scrutiny from the press and especially from her bosses, who balk at a woman holding the chief medical examiner position. At one point, someone sets her up to be fired by making it look like evidence from the Lori Petersen case was mishandled, potentially compromising the entire investigation. However, she insists her methods are solid, and Pete backs her up.

Someone also tried to hack into Kay’s computer in 1998, seemingly looking for information on the Petersen case. That call also turned out to be coming from inside the house: It was Dr. Reddy (Alex Klein), who had an ax to grind because Kay was made chief over him, and remains hostile to her in his present-day role as health commissioner. This revelation came via Kay’s assistant, Maggie (Georgia King and Stephanie Faracy), who, throughout the series, was painted as an adversary working with Reddy to take Kay down. Now, though, she’s ready to help expose her boss’s shady dealings, which probably includes why he covered up Cammie Ramada’s murder by pushing for it to be ruled accidental. Presumably, we’ll get into more of this cover-up in season 2.

What’s the secret Kay and Pete are keeping in 'Scarpetta?'

Kay and Pete’s relationship—as professional investigators, as family through marriage, and the fact that he may or may not be in love with her—includes a massive secret they’ve both been keeping about the night they tracked down Roy McCorkle in 1998.

When Kay identifies Roy as the killer, she tells Pete, and they plan to meet at his home to stake him out. But when Kay gets there, she hears screaming from inside the house and goes to investigate. That’s when Roy attacks and goes to strangle her like he did his other victims—until Kay grabs a piece of a broken ceramic plate and jams it into his neck, killing him. Pete arrives on the scene and covers for Kay by shooting Roy repeatedly, then claiming she was never there. When Kay does the autopsy, she lists his cause of death as gunshot wounds, making their lie the official record.

Where do things leave off between Kay and Benton in 'Scarpetta?'

These two kept big secrets from one another—including the truth about Roy’s autopsy. After Kay’s chaotic, drama-loving sister Dorothy (Jamie Lee Curtis and Amanda Righetti) drunkenly blabs to Benton that his wife has kept something major from him, the two wind up having a scorched-earth fight on their property, where Benton had been interrogating an FBI suspect without his wife’s knowledge.

Benton also has his own demons to contend with, stemming from dark and obsessive behaviors his mother identified in him as a child that he’s still trying to contain. As they’re having it out, he asks Kay for a divorce.

And what about Dorothy and Pete by the end of 'Scarpetta?'

After lots of tension because of Pete working alongside Kay—compounded by Dorothy’s over-the-top personality and worries about the closeness between her sister and husband—Dorothy and Pete wind up moving out of Kay and Benton’s home, where they had been staying while their house was undergoing renovations, and settle into a nearby Airbnb to regroup. Despite Kay saying she needs Pete’s help, he chooses to go with his wife, but things still seem uneasy between them. Dorothy’s fears about her husband being in love with Kay won’t go away that easily.

What happens to Lucy at the end of 'Scarpetta?'

Poor Lucy (Ariana DeBose and Savannah Lumar) has gone through it all season—essentially being raised by Kay as a teen when her mother was absent, and as an adult spending her days talking with an AI version of her dead wife, Janet (Janet Montgomery), while living in Kay’s guest house.

A lifelong tech genius, Lucy lends her talents to her aunt and stepfather’s investigation and becomes close to Blaise Fruge (Tiya Sircar), one of the cops also working the case. But there’s also a lot of fretting about how Lucy is coping: whether she’s too dependent on her aunt, spending too much time with her AI Janet, or both.

By the series’s end, someone has destroyed the AI Janet—it’s not clear who—leaving Lucy even more heartbroken. The final episode leaves her seeking solace at Matt Petersen’s grief commune.

How does 'Scarpetta' season 1 end?

The mystery-thriller series ends with a big new mystery. As Kay is bashing Officer Ryan’s head in with a baseball bat, someone opens the front door and catches her in the act. Who is it? And will they come to Kay’s aid, or try to blackmail her over what she’s done? We’ll have to wait until season 2 to find out.