Dexter plot point. Netflix's You season 4 trailer depicts a killer/stalker who knows about Joe's past. As the trailer reveals, Joe is using the alias Jonathan Moore and is employed as a literature professor in London. The You season 3 finale showed Joe in Paris, living under the guise of Nick and following Marienne. However, Joe's past is back to haunt him, as the killer texts him messages that indicate Joe might be getting consequences in the near future.
The identity of the "Eat the Rich" killer is a mystery to Joe and his new friends, a group that Joe describes as a "circle of privileged douchebags." While the friend group is new to Joe's life, they also could have a killer among them. However, there is a time jump that allows Joe to become Jonathan Moore, and what crimes Joe committed in that time frame could have provided new clues to the mystery killer. Joe has done his share of crimes, so there could be any number of reasons that someone would target him.
You's Joe Brother Theory Is Too Close To Dexter Arc
One of the theories behind the identity of the "Eat the Rich" killer is that it is Joe's brother and he is out for revenge. Reddit Designer_Basket suggests that Joe's half-brother Jakey saw Joe murder his mother. It is likely that Joe didn't take his mother leaving him for another family lightly. Since Joe has so much repressed shame around women, it could be that he killed his own mother in a rage after he learns she is leaving. After witnessing his half-brother murder his mother, Jakey could've stalked Joe and kept tabs on him to eventually avenge his mother's death.
However, this You season 4 theory would only exacerbate complaints that You has borrowed too heavily from Dexter, as this would be too close to the "Ice Truck Killer" arc in Dexter. You owes much of its success to the popularity of Dexter and has copied Dexter plot points in previous seasons. Dexter's "Ice Truck Killer" was revealed to be Dexter's older brother who witnessed his mother's brutal murder. When he was released, he began feeding his Dark enger by mutilating his victims. If You also features the twist of Joe’s brother being the killer, it would be another way that You has copied Dexter.
Who You's Best Killer Identity Choice Could Be
While any of Joe's new friends could be the killer, Kate is one of the least suspicious suspects and appears to be Joe's love interest in You season 4. Since Joe appears to be confiding in her, it would be a solid twist if she ended up being the killer. While some could argue that the elite gallery manager Kate isn't set up to be a killer, Love also did not seem the type to be a killer in You season 2. Kate's interest in Joe could be a possible friendship that she had with one of the women that Joe has wronged.
Another possible killer is Malcolm, a literature professor, who brings Joe into his elite group. He may want Joe to be seen mingling with the group, so he can later be framed for the "Eat the Rich" killings. Malcolm's motivations remain to be seen, but Joe could've slipped up in any number of ways that allowed Malcolm to want to stalk and punish Joe. The true identity of the killer may be revealed when You season 4 part one releases this Thursday, February 9th. Yet, knowing You, the show will take its time to reveal Joe's past and provide clues to the audience.