WARNING: This article contains spoilers about Riverdale season two, episode six.

The mystery killer is still on the loose in the instalment, titled Death Proof, and the Black Hood calls Betty Cooper (played by Lili Reinhart) to find out who is the main person supplying drugs in Riverdale.

Betty immediately finds Cheryl Blossom (Madelaine Petsch), whose father was the town’s biggest drug smuggler, to find out some information.

The flame-haired beauty then blackmails her mother Penelope (Nathalie Boltt) to tell her the truth about the Sugar Man.

When she finds out the identity, she relays it back to Betty who gives the name to the police instead of the murderer.

She warns The Black Hood: “I’m breathing down your neck. Can you feel it? Can you feel me?”

The Sugar Man turns out to be Robert Philips who is Jughead Jones’ (Cole Sprouse) English teacher at South Side School and newspaper advisor.

However, Betty’s plan to outsmart the killer fails as after the police arrest him and put him in jail, The Black Hood finds his way in and shoots the Sugar Man.

After the episode, many viewers believed the Black Hood had to be Sheriff Keller (Martin Cummins) as he would have been one of the only people who had access to the prison.

One person wrote on Twitter: "Good twist of who the Sugar Man was. How did the Black Hood get into the jail? Is it Sheriff Keller? #Riverdale."

"Let me get this straight, the Black Hood was able to sneak into the jail without being noticed and kill the Sugar Man? Sheriff Keller is the Black Hood confirmed. #Riverdale," said another fan.

A third was certain it was the town' s sheriff as they wrote: "Black hood is Sheriff Keller it's so obvious now. #Riverdale."

One person didn't want the theory to be true, as they commented: "I really don't want Sheriff Keller to end up being a bad guy #Riverdale."

Riverdale will be available to watch on Netflix today.