Plot hole: In the scene where she goes to her house after escaping there is no police tape on the front door even though it is a crime scene. Earlier the police searched and taped her office - it only makes sense that they would do the same to her house.
Plot hole: In the shower scene when Miranda is being cut, everyone in there, including the guard, sees her getting the cuts out of nowhere. Yet they all say, she did it to herself with a scalpel although one was never seen or found. Don't they think if she did it to herself, they would've seen it?
Plot hole: There's no way the guards couldn't see Miranda in the swimming pool. For one, you can see clear to the bottom of the pool. And their flashlights shined clear to the bottom. And when she emerges, she screams. They should've heard her since they just exited the pool area.
Plot hole: You are the police looking for an escaped madwoman who killed her husband and is in denial. Where is the first place you would look? If you said her house, congrats, you are smarter than the cops in this movie. Yet Halle Barry manages to spend the entire night there (she escapes just after midnight) crying over pictures without so much as a knock on the door.
Answer: Plain and simple, it's bad script writing and there's a number of other examples of "that wouldn't happen in the real world" that unfortunately we're suppose to accept. Although, if one had to justify it, you could say; when Miranda was in the hospital, she had not been tried and convicted yet, so when her trial did occur, Miranda's lawyers did not use the "I was possessed" defense and was found not guilty because of reasonable doubt. Or the DA's office made a deal with her because she was a high standing member in the community who exposed a number of issues and may have gotten parole instead of jail time. And Chloe was Miranda's patient before she herself was admitted to the psychiatric ward. At that time, Miranda never believed Chloe was anything but delusional and after spending time in the hospital as an inmate, she believed her and once she was free, she worked on getting Chloe released by stating she was not insane.
Bishop73