From https://murderpedia.org/male.B/images/bamber_jeremy/20011745.pdf part of an Appeal Court document.
"17. Shortly after the marriage Sheila’s mental health began to fail and the couple divorced in
May 1982. During 1983 Sheila was admitted to a psychiatric hospital and subsequently was
diagnosed as a paranoid schizophrenic. In March 1985 she was re-admitted to hospital
before being discharged a little under four weeks later. For the months before their death,
the children had been living with their father, although seeing their mother frequently. On 4
August 1985 (three days before the killings) Colin Caffell had taken his ex-wife and
children to spend a few days with their grandparents at the farm in Essex."
Did Collin Caffell have a watertight alibi for that night?
I think (but I'm not certain) that he lived with his then-girlfriend, Heather, so I would think his whereabouts would be confirmed by her, if they needed to be. He drove back home from Essex to London a few days before the incident and was at home when the news was broken to him by two WPCs, who visited him.
If Jeremy did this, then Colin Caffell is the biggest surviving victim of the incident and he ought to have everybody's unqualified sympathy. I must admit - and I feel slightly ashamed to say this - I have never been able to feel complete sympathy for him, though. I'm not sure why. I can't put my finger on it, but I've never taken to him. I have always thought there is something fundamentally disingenuous about him.
But a murderer? No. No way. Impressions aside, he had no motive at all, I think he loved the twins, and he did not have (nor does he have) any significant mental health issues, to anyone's knowledge. Has he any knowledge of or association with guns at all or even ever fired a gun? I'd be surprised. He's just a normal man caught up in it, and quite genial. I struggle to even imagine him losing his temper, never mind murdering anybody.
New angles are welcome, though, so if you have one, let's hear it. Putting my legal hat on, I would take great care when making novel accusations against specific surviving individuals. It's one thing to 'do a Mike' and say David Boutflour was the Hunched Man, or whatever - I doubt the English libel courts will be much interested, either way - it's quite another thing to accuse a harmless, genial, naive sculptor who's done generous rehabilitation work in prison with lifers of being a murderer himself.