It is common for sure. But I really do not get that vibe here. There is obvious psychopathy here with both of them in the PD department. LT gives me possible Intellectual Disability ( In the HIGH range) vibes and definite possible serious mental illness (Bipolar Disorder maybe, lots of impulsiveness there ) with a personality disorder. They can exist at the same time in one person. Borderline..I'm not positive. BPD is more about splitting and raging and then swinging back to idealizing. It stems from the primary caretaker not allowing for proper separation-individuation early in life and then in adolescence. They fear abandonment above all else and perceive it everywhere. Its a serious void of self and of pathology in attachment style.
That being said, forensically, they knew right from wrong. They were calculating. And knew to hide what they were doing .
But I will eat my hat rather than say there is no mental illness here. Regardless of what authorities have said. Hoarding in and of itself is a DSM5 Diagnosis. They also said it way to early, not leaving enough time for a comprehensive mental health eval of both of them. Not for insanity purposes of course. They were NOT insane and should pay for what they did.
I see psychopathy in the PD department , psychopathic personality disorder, or even Antisocial ASD, MOO. There is not enough there for me to assume borderline yet. (Cutting, self harm, splitting etc). BPD generally cut themselves, high suicide attempt rates, the rage swings from being directed at ones self and then to others. All of this rage appears to have been directed at their children. They also have very high interpersonal conflict, chronically. She has been in a "stable" (VOMIT) marriage for 30 something years.
Who knows. We will see. We don't know enough. What we do know is that their behavior is depraved and sadistic, and calculated. They knew what they were doing and knew to hide it, has been going on for many years. They hoard, live in squalor, destroy and abandon house after house, blow through money, and the cycle starts all over again. There are impulse control problems in both. Serious regression in LT. Sexual predation in DT. A lack of compassion, empathy, and insight. They did not appear to care one iota. Its gruesome, grotesque, and defies logic.
Hoarding is also usually born out of trauma. LT appears very regressed. Stuck. I would guess there was trauma in her childhood.
ALL MOO.