The mystery of who killed Jason Blossom (Trevor Stines) has been hanging over "Riverdale" since the pilot, and it looks like it's a question that won't be answered until the end of Season 1. Theories abound about which characters are guilty, which are innocent and which are just too confusing to tell -- even for the cast.

We sat down with the stars of "Riverdale" during the TCA Winter Press Tour to ask who they thought killed Jason, and their answers spanned all over the map.

From the very likely Coopers, to the wild Hiram Lodge guess, to the Blossom parents themselves, the cast seemed to run through every single suspect possible.

RELATED: Why are the adults of ‘Riverdale’ so freaking awful?

Madelaine Petsch, Miss Cheryl Blossom herself, came up with an interesting theory we think deserves some credit: What if Miss Grundy (Sarah Habel) did it?

We only had a handful of episodes with Riverdale High's worst teacher before she was driven out of town for her inappropriate relationship with Archie (KJ Apa). While she was there, however, we were clued in to a few very important details that could point towards her as Jason's killer.

We already know she's got a loose relationship with the law (and just morality in general), considering she was sleeping with a student and looking at underage boys like slices of meat. This little tidbit only gets worse when you remember she used to tutor Jason Blossom. Could she have been carrying on the same kind of predatory relationship with Jason as she was with Archie?

Now that we know the gunshot Miss Grundy and Archie heard in the woods that day wasn't the one to kill Jason (it was fired off by a seriously questionable Cub Scout troop leader), Miss Grundy's alibi goes out the window. Did she and Archie stay together that morning, or did she go off on her own -- into the very same woods where Jason was killed?

RELATED: ‘Riverdale’s’ Cole Sprouse previews Jughead’s ‘Greek family tragedy’

Finally, what about that gun in Miss Grundy's glove compartment? Sure, her story about an abusive ex-husband could mean it's just for protection, but most responsible gun owners don't keep their firearm stowed in their car where anyone could get to it. The fact that she owns one in general is suspicious considering Jason's cause of death -- a bullet to the head.

Petsch eventually second-guessed herself, but until we see why she shifted her suspicions to the Blossom parents, we're still guessing Grundy is to blame.

"Riverdale" airs Thursdays at 9 p.m. ET/PT on The CW.

Posted by:Lindsay MacDonald

Lindsay MacDonald is a Los Angeles based entertainment reporter with an affinity for CW superheroes. She graduated from Pepperdine University with a major in Media Studies and a borderline unhealthy obsession with TV in 2012. She would much rather spend the day binge-watching ‘The Flash’ or sorting ‘Game of Thrones’ characters into Hogwarts houses than venturing outdoors. TV words to live by: “Never ignore coincidence. Unless, of course, you’re busy. In which case, always ignore coincidence.”