Just to add one more important observation to my theory 11376

RJ's victims have mostly been women (when he started killing) - in other words, when he was younger. At this stage he was possibly still unable to control the urges guiding him (until he started channeling his 'tendencies' - possibly after spending time with Mr Stiles: into far greater things than simply killing - a criminal empire)

When women are victims of serials (his earlier victims) one usually pulls up a mommy issue. Kirkland has serious mommy issues.

Mother killed herself to escape a brutal marriage, leaving the twins behind to take all the cruelty and pain alone. In Bob's mind his mother abandoned them, leaving them to take a world of emotional and physical hurt from a sadistic father.

'I won't leave you'....said rather sarcastically as Lennon is dying.

Could this not be the ideal kick off for a young RJ? Those smiley faces have always come across as 'child like'. A crying child's face trying to cover the tears with a 'fake smile' - exactly how a young person would feel after a mom's suicide, 'perceived abandonment' to a life of pain with an almost satanic father.

So mom's suicide is Bob's emotional trigger. (How did she kill herself? Perhaps she slashed her wrists with a linoleum floor cutter - which would finally explain to me why RJ uses such a weapon.....it's a household item from a father's garage type of weapon IMHO)

RJ is born.
Finds his way to visualize
Starts killing women (and others), and signing his scenes with the 'child's crying/smiling face'.
Brett Stiles sees huge potential - but needs Bob to channel that sociopathic potential in a way that is bigger, better. Eventually TT is born.

Maybe?

Anyway, Kirkland is also the only suspect who has given us the 'mommy suicide' story - what a trigger for the dawn of RJ.