Ideas for my own TV drama

For one of my tasks, I have been asked to develop a pitch for my own TV drama which includes a plot, setting and characters/actors. 
I have thought to do a TV crime drama as I find it very interesting. My TV drama would be set in New York. A couple who have just gotten engaged move to a new apartment. The male who is called Tom gets a new job as a journalist which means he is away a lot of the time. His fiance is often left by herself at home and starts getting doubts about her relationship with Tom. One day when Tom is away, his fiance Emily, gets suspicious and asks his colleagues how long it'll take for Tom to come home (she makes it less suspicious by saying his phone is off and she is unable to contact him) but they say that Tom hasn't been at work for the past 3 days, which means that he has been lying to her. Emily begins to stress and cry, realising that the only reason why he could possibly be lying because he cheating. She isn't thinking straight, and thinking about what she can do to keep him, but then she begins to think that maybe Tom never loved her and was only using her. She begins to over analyse the situation and then thinks that he can't be with anyone but her so the only way she can make sure of that is if she kills him. Excited by this thought, Emily begins to plot the murder of her fiance even though she has no evidence of him cheating on her. Emily plans to strangle him when he gets back as she wants to make him suffer. When Tom gets back from his mysterious get away, Emily is awaiting his arrival. When the couple go to bed and Tom is slowly falling asleep, Emily begins to strangle him and kill him. When she kills him she flies into Italy and it all becomes certain to Tom's family who killed him and the hunt for Emily goes on.