Three of a crime Card game

[gattamaneni abhiram <abhiram.gattamaneni@gmail.com>]

Three-of-a-crime is a simple logic game for up to 3 players. There are 7 different 
criminals. The computer randomly chooses three of these (the "perpetrators"), but 
doesn't tell the players which are chosen. The computer then puts down three random 
criminals. 0, 1, or 2 of these may be the actual perpetrators. The computer also tells 
the player how many (but not which) of the three criminals are perpetrators. The 
players may either guess which three criminals are the actual perpetrators or they may 
pass. If a player guesses wrong, she is out of the game and the other players continue. 
If no player chooses to guess, the computer puts down another three randomly chosen 
criminals (0, 1, or 2 of which may be actual perpetrators) and tells the players how 
many (but not which) of these are actual perpetrators. Players can again use logic to 
deduce the three actual criminals and may guess. Play continues until some player 
guesses correctly or until all players have guessed incorrectly. 

I am not able to deduce the logic. Can anyone please help me with the logic?