Poker card array

The killing game is played roughly like this: 8- 12 people sit together, and then determine which cards are policemen and which cards are killers, and draw lots or recommend them by playing cards: one is the judge presiding over the game, 2-3 are killers, 2-3 are policemen and the rest are civilians. At the beginning of the game, the judge announced: Please close your eyes when it is dark, and then the killers will open their eyes.