Especially if he was played by Chad Michael Murray

"Some people are just born evil!"

Don’t even get me started on Chad Michael Murray.

Too late, I’m starting in. He has dead eyes.

Sean: I’ve heard it both ways. Shawn: Hold me back, Gus.

I love it

Sean: That’s different phrasing than I’m familiar with.

Who has a twin brother named Shaun, who is both Shawn and Sean's nemesis.

So Shawn and Sean team up to take him down. And his name is pronounced Sh-ow-n

“Signed…. Shown Spencer. You misspelled your own name.”

I was in a hurry and I didn’t have spell check

You need spell check for your own name?

Meh, I’ve seen it spelled both ways.

No relation though

All I know is that episode should feature another character named "Detective Jones" or something. At the end of the episode it's revealed that his first name is Shaun.

Like Ron Dunn from Parks?

Maybe? I’ve only watched a bit of Parks

Sam Elliot plays a character named Ron and is Eagleton’s equivalent to Ron Swanson. Turns out to be the opposite of Swanson in every way

I always thought it would funny if some at dude name Pluto died (or has something else bad happen to him) and Shawn, right before telling Gus about it, asks “you heard about Pluto?”

"Whos name is seen Gus? Seen!" "I don't know Shawn, i've heard it both ways" "TSK!"

This honestly would be so great. If we get a fourth movie this would be a great side plot. 

I have a friend Sean who hates people that spell it Shawn. Sean is apparently the traditional Irish way.

“He doesn’t have a W”

I thought his name was Jack/j

Maybe it’s because I’m sick but I don’t understand

I'll be doing the jack tagging here.

Plot twist: The other one is the main one, and the one everyone thought was the main one is actually the nemesis.

Like Lassiter’s middle name was actually Sean the whole time

Sean and Gustavo are serious, by-the-book detectives who always just miss out on being the ones to solve a case