Betty Cooper has been actively involved in all the ongoing events in Riverdale ever since the show returned with season 2 and yet another mystery. This time, letting loose a masked murderer in the town, which was still mourning the tragic loss of Jason Blossom, killed by his own father Clifford.

So far, the mysterious killer – who goes by the name of Black Hood – has targeted Fred Andrews, shot two Riverdale high students, Moose and Midge, and strangled Miss Grundy — Archie's former love interest — to death.

Except for a distinct pair of green eyes, not much has been revealed about the shooter, but fans might beg to differ.

Several fan theories have since then cropped up on Twitter, suggesting that the hooded killer is related to the Cooper family.

Viewers will remember that in The Watcher in the Woods episode of season 3, the gun-wielding man reached out to Mrs Cooper with a note to warn his victims, who he described as the "adulterer", "child predator" and "drunk and sex-addicted teenagers".

In fact, the dramatic turn of events even upset Betty's older sister Polly, who is pregnant with her dead boyfriend's children. Considering that the Coopers have been in the middle of all the drama, viewers have now come to believe that the mystery killer could very well be Betty's brother, Chic.

Previously, the name was mentioned when Betty confronted her mother, only to learn that her older brother — from Alice's past relationship — was given up for adoption. The fact that Chic will soon be a part of this twisted circle, was made clear when actress Madchen Amick shared a set-photo on Instagram.

"Look who I found roaming the halls of #Riverdale High..." she wrote tagging actor Hart Denton in the post — who will be playing Alice's son.

"Plz help me welcome our latest addition to the #Cooper family @hartdenton -aka- #ChicCooper ...buckle-up sweet boy, it's gonna be a wild ride!!!" Amick added.

In the town of Riverdale, however, one can only be certain of the next disaster. The CW show returns with season 2 episode 4 — The Town That Dreaded Sundown — on Wednesday (1 November) at 8pm EST.