Head to Andreas' yacht to introduce yourself and get your 'first' mission back in the Assassinos. Remember, you are now 'Angel', not Raul. The mission is to scare the State Prosecutor, who has been hassling Marcelo with a court case.
First, head to the Courthouse. There you will find the State Prosecutor's driver, who you need to beat up.
TIP: You are not required to kill the driver, but you will earn an additional 210R$ if you do.
Once that's done, get in his car. You are basically awaiting the State Prosecutor and pretending to be his driver. Once he gets in the car, drive as irresponsibly as you can to scare him. This can include hitting objects, swerving all over the road, driving fast, and driving on the wrong side of the road. Once the irresponsibility meter gets to the top, the game will stop the car and you will let the State Prosecutor out - once he agrees to drop the case against Marcelo.
Reward: 2,000R$