Help ID a TV show--crime drama in which family is killed in hotel room

I’ve spent some time in Search but came up empty; for one thing, I’m not sure what year the thread on this particular show, whatever it is, was active. Not this year; not last year–back further, I think. (I started here in 2013 so it’s after that, at least!)

The show I’m trying to remember featured a multi-episode mystery about who had killed a family in their hotel room. I’ll spoiler this next bit in case the show turns out to be one that’s still being shown in repeats: The killer turns out to be the teenaged son, who has a crush on an adult woman and believes that his only way of hooking up with her is if his disapproving parents are out of the way. There’s a crucial scene in an early episode in which the kid is walking down the hallway of the hotel, away from the room in which no one yet knows his dead family lies. He’s dressed for swimming, on his way to the hotel pool.

This is driving me crazy. Usually I can remember one or more performers in the show or movie I’m trying to recall, permitting an effective search, but in this case I can’t recall a one.

I know we discussed the show here in Café Society, but, again, am not sure when, or even if it was in a dedicated-to-that-show thread. I’m not sure if it’s an American production or UK (probably one of those, anyway).

Anyone remember this?

The Americans?

Hmn, that’s possible–there were several instances of kids being seduced by the Russian-in-disguise wife.

At least that gives me something to search (the name of the show) to see if there’s a thread discussing that plot development–thanks!

Jared Connors would be first choice:

https://theamericans.fandom.com/wiki/Jared_Connors

Jared Connors was the son of Emmett and Leanne (both undercover KGB Directorate S agents) and the brother of Amelia. He murders his family in their hotel room. He later confesses to the murders and reveals his knowledge of his parents’ true identities.

Okay, so that IS what I was trying to remember—thank you, The_Other_Waldo_Pepper and don_t_ask !!

I’m not even sure why this came into my head, but it’s been there, annoying me, for a couple of days. Sweet relief!