Enter this code at the "killer8 press start screen" (right after you lauched the game)

(Use a Steam, Xone, X360 or GC controller for an easier inputting of the cheat code)

Down, R, Up, L, Y, B, X, A.

Once you hear the Recovery sound effect, it means the cheat was inputted correctly. You will obtain 100 free Serum vials when you'll visit the first Harman's Room in the Celtic Bldg, but keep in mind this will only work in killer8 mode! Note: Once you beat killer7 either in normal or hard difficulty, you will unlock killer8, a hardcore version of killer7.