S6E15 THE KILL JAR

The island family tree is quite the Kill Jar:

CRAZYMOM kills Claudia to take Jacob and MIB; kills Claudia's people

MIB kills CRAZYMOM

JACOB kills MIB and throws body into Light to create SMOKEY

SMOKEY kills Black Rock crew except RICHARD; kills Rousseau group except Rousseau; kills Others except WIDMORE & ELOISE (plus Cindy, Emma & Zach we think); kills misc. 815ers

ELOISE kills Faraday

WIDMORE's men kill Others, 815ers, Rousseau

BEN kills DHARMA in purge; kills LOCKE; then kills JACOB at SMOKEY-FLOCKE'S urging to create Ghost Jacob

815ers and Others kill each other.

I think the only person left on the island who has not directed killed someone may be RICHARD, except he was with the Others who helped BEN with the purge, and gave Locke the intel to have Sawyer kill Cooper. At this point we do not know whether ROSE and/or BERNARD are still alive on the island in 2007, so the only person without blood on her resume would be ROSE.

So everyone on the island has something in common: they have been part of a murder.