The serial killer didn't kill Tyrese's son and daughter. They had a suicide pact and that's how they found out how the virus really works.

The serial killer in the comics was the nerdy convict named Thomas and he killed Hershel's twins, Susie and Rachel...he decapitated them in the barber shop, if you remember, when they walk in the find the twin children sitting in the barber chairs with their heads removed.

I really think they down playing Michonne character too much , she dont have no say in any conversations , also Andrea  going to die at the end of season saving Rick and company , only cuz she dont fit in with either the Govenors crew or Ricks . Still its a rockin show .

SPOILERS!

Thanks MJBE and fatpantz, I was just about to say that.

Also, violator, in the comics, Tyrese ended up being one of the main characters of the series and met an untimely and SHOCKING death. I won't spoil how he died here, but let's just say that combined with the other deaths from the Governor's raid, it's still one of the most shocking scenes in all of the comics (next to what just happened to Glen in the comics).

And I'm going to go out on a limb here, but I don't think they're going to kill off Andrea. Merl, maybe. Andrea, no.

I hope they don't kill off Merl, because I like the dynamic he brings to the group, but I don't really see him surviving the ultimate fight between Woodbury and the Prison.

But I think Carol's number is near up. And the same goes for the baby. And if the show really wants to bring the bombs, Hershall, Carol, Beth, Merl, and the baby will all die, along with the Gov, Milton, and the other two dorks with Tyrese's group.

One person besides Rick who should not die: Daryl. If they kill Daryl, they'll lose millions of fans.