In the opening scenes, three shots are fired and we see that Christine, the suspect, and her dad have been hit. Christine is holding her left shoulder. Yet when she leaves the dispatch center she has a brace on her left leg and is using a cane.
Christine uses a cane and clearly has trouble walking, but after the hearing in the bar she is walking without any problems and also initially at the crime scene. She then again has trouble with her knee at the crime scene.
In the flashback to the original shooting, four shots are heard, whereas in the original footage only three were heard. The fourth shot would explain Christine's leg injury.
Christine's badge changes from an LAPD oval badge in her apartment to a different style when she is walking up to the crime scene.
Police departments do not allow relatives such as fathers and daughters within the agency to work patrol, as it is thought that emotional ties would cloud an office's judgment.
A police employee while on suspension cannot carry a gun or badge.
Crime scene markers are not left at the crime scene. They are used for photography and then removed.
The first two paragraphs of the news story Christine reads on her laptop are about the murder, but after that it is about someone named Garnett and their many ailments. Whoever wrote the copy for the movie gave up after the first two paragraphs and just used filler for the rest.
The lock on the door the kid uses after resetting the breaker is on the wrong side of the door. Locks are always on the same side as the knob. A lock on the hinge side would be ineffective and of no use.
In the opening scenes, Christine makes a rookie police officer error with fatal consequences- she does not handcuff the suspect before searching him.
Christine has evidence of a burglary at her apartment and does not file a complaint.
Tim illegally searches Monty's apartment and takes pictures. As an officer, he'd know any evidence he obtained there would be inadmissible due to an illegal search. This is rendered moot when Christine kills the suspect.