TK has been killed. Who killed them? (WARNING: THERE ARE 2 MURDERERS!)

Vee: Oh, TK? I didn’t go near that guy, honest.

Hoppy: I was running laps around the house and when I came back inside they were dead!

OWAKCX: …

Keroppi: I dunno what happened to them…I was just in the kitchen making lunch!

Gummigoo: I-I was in the living room and the p-power went out…Then it came back on and they were dead..