Was Reza resentful to the man because of his abuse of her?
Did she start to plan his murder after he kept her captive?
On that note, did she plan his murder because he kept her captive?
Was the captivity an actual one (e.g. in a cell), or another type (emotionally, socially, etc.)?
Could she have easily escaped from her captivity?
Did the other person involved help Reza conduct her murder? Help the man abuse her? Caused Reza to resent the man?
Is the other person related to Reza? To the man?