Rebel Cops

Can easily be obtained quite early on in the game, either after the Estate mission, or after one of the shorter missions just after it. Take on and complete all side missions offered, and always give 85% of your earnings to the public. To get the chance to give your earnings to the public, you'll need to have collected most of the valuables in the level, then sell everything when given the choice after the mission. Side missions usually give +1 Street Cred, and giving 85% of your earnings to the public will increase it by another couple of points.