What do you guys mean when you say BBM?
Not to go on and on here, but a couple more things that stuck out to me re: JA's probable psychopathy:
-When Det. Flores asked her who the aggressor was, she answered to the effect of "I don't know what you mean by aggressive." Again, psychopaths are not in touch with emotions the same way we experience them, nor do they understand proper social boundaries.
-They see people as objects to possess, and I saw an interview with one of the victim's friends where they said JA made it very clear that Travis was "her's," "my boyfriend," "my house" (really his house), etc.
-Psychopaths are very, very impulsive, and have a low tendency to plan long term. This is partially why they often move (JA's multiple roommate situations), travel (JA the "roadtripper"), change jobs, and are generally unreliable. She kept obsessing about why she wouldn't have worn gloves; IMO she wishes she had worn gloves and doesn't understand why she didn't plan it out better, because she has little insight into her own behavior. As some other posters said, I agree that she may have considered letting him live if he'd agreed not to take another girl to Cancun, to resume a relationship, etc...and when it didn't go that way, her rage and impulse took over. However, the possibility of ending his life was likely on her mind before she even got there, as she probably brought the weapons with her, and left him a creepy message beforehand like "see you soon, my friend."