In this chapter you'll find the description of assignments available after choosing specific Shepard's background. They all take place on the Citadel and it's best to complete them during second of third visit there (you have to complete at least one of main plot missions: Feros, Therum or Noveria).
You'll find a man named Finch in the lower wards. He'll remind you of your past and threaten to reveal the secret of you being a member of a gang unless you'll help him rescue his friend from C-Sec.
Head to Chora's Den to talk with turian guard. It looks that Finch's friend was caught at murder's attempt. You can use charm/intimidation to persuade the guard to release him (renegade points). If not, Finch will show up and threaten to destroy your reputation. You can use charm/intimidation to calm him down. If not, he'll want money for keeping your secret unrevealed. You can pay him, try to persuade him again or just shoot him. Each possibility will end the assignment.
While riding the elevator in the Citadel, you'll hear a message from lt. Girard. He'll ask you to come back to Normandy. A woman from Shepard's native planet threatens to kill herself.
Girard will give you the sedative and ask you to talk with her. She can be found near the entrance to Normandy. Your task is to approach her without causing too much stress. Talk to her constantly using persuasion. When you will be close enough you can give her the sedative or applicate it yourself. Return to Girard when you are done to complete the assignment.
In the passageway between Presidium and wards (Wards access map) you'll meet a man named Zabaleta who claims to be friend of Shepard's mother. He'll ask you to give him 20 credits.
Come back to Normandy communication room and talk with your mother. She'll confirm she know Zabaleta and ask you to convince him to go to the veterans affairs office.
Come back to Zabaleta and talk with him again. You can use persuasion to convince him to go there. If not, give him the money (no morality bonus), give him the money for food (paragon points) or just leave him with nothing (renegade points).