I would say that whoever shot and killed the parents did so in a deranged manner, spontaneous violence, that these two deaths were not carried out in a cold caalculating manner at all. The person with the loaded gun was literally going berserk when that person shot seven bullets into June Bambers body, and as many as eight bullets into Neville Bambers body. Both parents were covered in blood, their deaths were not quick and clinical, they died an agonisingly horrible death as a result of being attacked in a frenzied manner, in my opinion...
In the case of the two young children, whoever shot and killed them appears to have gone out of their way to make sure they felt nothing, and knew nothing...
The killer whoever that person was adopted a different approach when shooting and killing the children, than was adopted when the parents were shot and killed! I do not believe that a psychopath could differentiate such an approach when killing multiple victims, in one session! I should imagine its all out rage and destructive violence being directed at everything and everyone, man, woman, or child...
Something is nagging at me, its as though whoever shot and killed the two little children, did so with a degree of fondness and love in their heart, the shooter did not want the little ones to suffer, as compared to the hatred exercised when the shooter turned the gun on the parents...
That person was Sheila Caffell, not Jeremy Bamber, I have no doubt whatsoever in my mind about that...
Sheila did not kill herself, as the prosecutions case alleged, she was killed, indeed, shot and killed on two separate occasions by a third party!
You then have to believe Sheila was acting rationally and therefore not in the grip of a schizophrenic episode, when the "
all people are bad and should be killed " remark of several weeks previously re-entered her head.
In my opinion it was Jeremy who crept into the twins' room first to test the gun, disabling the twins with one shot to the head each, then dispatching his parents in the master bedroom with what he thought would be enough with the remainder of the load, returning to the twins' room subsequently to secure in an arc pattern their demise.
None of this typical of Sheila with her lack of synchronization between head and hands, unable to place the final shot to June right between the eyes, nor would she have lain down on the bed with her mother, who in your scenario was the most hated individual in that household. Her whole serene demeanour and blood spatter on the nightie suggests her death was quick, occurring from the sitting position, Jeremy pulling her legs following the second shot to convince himself that she was finally dead.