Steve Tampio is a minor character in Power. He first appears in Season 5 and makes a guest appearance in Season 6.
Season 5
Steve Tampio briefly has a relationship with Angela, and Angela tells him about Dre testifying against Alicia Jimenez. When Tommy and his crew try to kill Dre in a warehouse, Tampio shows up in a van and tells Dre to get in if he wants to live. He says that he is there on behalf of Angela, and he gets Dre to sign witness papers to testify against Alicia.
Season 6
He attends Angela's funeral and Saxe recognises him. Steve Tampio mentions to Saxe that Angela put him onto Dre to close the Alicia Jimenez case, which Saxe was unaware of. Tampio says Dre might recant if he finds out Angela is dead and tells Saxe to make sure that doesn't happen.