I just wonder if he could be.

I Wonder how he would act if someone told him,
"I know what you did. I'm going to tell the police everything."

Serial Killer
"someone who murders more than three victims one at a time in a relatively short interval."

No he isn't. Well according to Web definitions anyway.

He could be the answer to all our prayers:

Fiz - "You'll die frizzy and all"
Me-chelle - "You'll die with your arms folded and all"
Cotton - "You'll die a poor outdated caricature and all"
Anna - "You'll die a taaaaaaaaaaaaaaaaaaaaart and all"
Katy - "You'll die on the stairs and all"
Eileen - "You'll die horrible and all"
Jason - "You'll die a PhD Doctor of Rocket Surgery and all"

One can only hope.

He's killed one woman, Tina.

You do the maths and tell me if that makes him a SERIAL killer?

And it's not referring to sugar puffs.

No he has only killed one person at the moment.

lol