Yeah! all these new characters you see while playing the multiplayer of Red Dead Redemption are indeed secret characters. These characters we are going to unlock are Free Roam Characters which are not found in outfitters.
Now back to how you can unlock these secret characters, this workaround works on random bases, the character you get will be random so don’t expect your favorite character to pop out real soon, you may have to give few tries before you get it.
How to Unlock Secret Characters in Red Dead Redemption
You will need to delete your multiplayer save file. If you have Xbox 360, go to”System Settings>Hard Drive>Games>Red Dead Redemption> (Multiplayer save game)”, and delete it. PS3 fellas can follow the same procedure with respect to their console.
Note: You can backup your save file to be on the safe side.
Run Red Dead Redemption again.
Press “X” at main menu, to start multiplayer.
Create a new Save.
Save it to hard drive and wait until the game loads.
Now you will get a new character, everytime you do that, you get a new character. You can repeat it as many times as you want.
Now if you have created a new save and have your favorite character and would like to continue from start, you may want to read Red Dead Redemption Fast Level Up Guide.
Thanks @ Joe Careaga of Red Dead Forums for Tip