She is portrayed by Maria Rivera.
Maria and Miguel were kidnapped by Tommy and the other crew as Miguel shot up Cruz to steal a shipment, they are kidnapped under the Truth nightclub in the warehouse on Ghost's first night of opening up, Maria is let go and Miguel is shot dead.
Maria is later working in the café and sees Ghost on TV with Rashad Tate and Andre Coleman she pauses herself and comes to the FBI. All though she didn't see Ghost but she did remember his voice, so she then goes and speaks with Cooper Saxe and John Mak.
Maria is explaining about what happened, Saxe and Mak are investigating the situation, Mak eventually stops after Tony Teresi is later shot to death, but as Ghost and Tate are doing a press about a Queens project, Maria is there staring him out, then she gets on to witness protection and builds a trial with Saxe to take down James. When James finds out he believes that Angela Valdes is the witness who is later shot to death by Tommy Egan.
Ghost later finds out that Maria is the witness and tracks her down. Instead of killing her he pays her alot of money to keep her mouth shut and she is scared badly. Maria takes the money but refuses to not testify. She is later tracked down and killed by Tommy after he finds out about her.