When a team mate betrays and kills another team mate in the alliance, they become a traitor. As usual, the person who dies leaves the alliance and respawns as a cop.
The traitor's Gamertag above their head will become orange. Once this happens, make sure you head straight for them to win the cash reward for killing them and the extra traitor kill toward this achievement. Walk over their body to collect their dropped cash (and for satisfaction).
These methods can be adapted for more people, but generally it's best to stick with 4 or 5.
Boosting method for 5 players courtesy of
F4775:
We'll call the players 'Player 1-5' for sake of this guide.
player 1 kills player 2,
player 3 kills player 4,
player 5 kills players 1 and 3 for two traitor kills.
Player 5 could now escape with all the money to work towards the
Mr. Play-It-Straight achievement and the
50 to Won achievement. Then again, they could commit martyrdom by means of a grenade to make the round end quickly. Rotate players so all get even kills for however many rounds or kills you need.
Boosting method for 4 players courtesy of
MarkLaing07Note that this method is less efficient than with 5 players; you'll only gain one traitor kill, but you do gain a personal revenge kill which could be of use if someone needs them.
Again, for the sake of this guide we'll call these players 'Player 1-4'.
Player 1 kills player 2
Player 3 kills player 1
Player 3 "cooks" a grenade
Player 4 kills player 3 and stands over the grenade to end the round
Tracking your progressYou can find the counter for your traitor kills in the menu; visit 'Multiplayer' and select 'Stats'.
Keep in mind that your personal revenge kills are added onto your traitor kills. To find out the true number of traitors you've killed, subtract the number of personal revenge kills from your traitor kills.