- No, not the monster who killed Superman... but he did kill Charles, the Detective.
Doomsday was selected by a malevolent being known as Elgador to be one of his minions for some reason. Elgador summoned him by placing a portal in front of him. Doomsday was partnered with Kundabar the Elf, a dark elf who was even more evil than he was.
Elgador tested the two by putting them through challenges, which they both passed with flying colors. When Kundabar encountered and tried to kill Charles, the Detective, during one of the challenges, he tried to kill him but was unable to alone. Doomsday decided to join in the murder and the two seemingly killed him. The two then attacked Elgador, but were overwhelmed, and Kundabar soon died. Doomsday, however, was able to kill Elgador just as he died himself. ("MaNiPuLaTioN")