Which serial killers are mentioned in Gavin and Stacey?

It's one of the most beloved (and iconic) British sitcoms of all time, but there's a sinister undertone to Gavin and Stacey... and it's not *only* the presence of James Corden.

Corden and his co-writer Ruth Jones gave a subtle nod to some of the UK's most infamous serial killers - but do you know who they are?