Probability Calculator

I have created an online interactive probability creator which you can find here.  This is still formative and feedback is welcome.  Eventually I want to make it so that you can save your own settings.  It is difficult to find items of evidence that incriminate Robin.  While doing it I realised how incriminating the blood on the back of David's T-shirt is.  How on earth did he get that by going round inspecting the bodies!?

The other item that struck me was the trigger lock key.  I understand that Robin already had the principal key in his possession, well, at least in a coat in his caravan or somewhere, as a result of keeping while David went for a swim the previous day.  Was it determined that the spare key was used to unlock the trigger?  Was the principal key still on the necklace in the pocket?  If Robin had wanted to commit the murders he would not need the spare key since he already had the principal key.  Any enlightenment on this by experts out there would be appreciated.


Yes Kent the blood on the

Yes Kent the blood on the lower back of David's T shirt which was the biggest smudge of blood is very incriminating there was also blood on the front left and upper back. Yes the principal key was still on the key ring in the jacket in the van and it was the spare key from the pottery jar in David's room that was used to open the trigger lock. Yes it is extremely hard to find evidence against Robin perhaps you could phone Joe he should be able to concoct some for you. Just tried the calculator will there be a whole lot more questions?

Well, half the reason for

Well, half the reason for making this post is to get some feedback on what questions  to include.  I do not want to prejudice David Bain too much.  He is already overly prejudiced.  So fire away with your suggestions.

imho i think the jacket and

imho i think the jacket and keys were a plant

great work on the calculator


I'm not sure if the "experts"

I'm not sure if the "experts" would agree with you on that.  Anyway, the calculator will now save your settings if you are registered and logged in.

Trigger lock keys

David Bain said he left his anorak with the key that he usually wore round his neck in the pocket in his father's van when he went for that polar swim,but we don't know that.
When he was on his paper run one witness said he thought he was wearing an anorak and another witness said he was wearing a sweatshirt with a hood and that the hood was up.
David Bain said he put the sweatshirt he was wearing on the paper round in the washing machine when he arrived home. That sweatshirt does not have a hood.
We all believe David Bain did the washing before he went on his paper round. He was away for an hour so the machine would not be going when he arrived home.
So it follows that unless he rinsed that sweatshirt and put it in the washing machine to make it look as if he had put it in when he arrived home,he must have put it in the wash before he left on his paper round.
That means he was wearing his anorak on his paper round.
But why would he have put that anorak in the van when he arrived home?
One possibility is that he always intended to replace the trigger lock key that was found in his bedroom with the trigger lock key that was in his anorak.
That way he could say his father had access to the trigger lock key because it was in the van.
But because his father was late coming into the house he just forgot to do it.

So there is nothing definite

So there is nothing definite about the trigger key.  Was the van which they used to go to the swim different from the van that Robin used to sleep in?  I think there is a certain amount of murk regarding the evidence and one can't speculate too much.  Certainly Robin could have accessed the key somehow, so the key evidence does not preclude him entirely, but it puts greater weight towards David, that and the fact that David owned and had control over the gun.



Robin only used one van.

So he slept in the same van

So he slept in the same van that he commuted to work and which he might have carted round his family in.

One van

Their was a second derelict van at the school with weeds growing up through the floorboards. I believe it may have been roadworthy for a while but it certainly wasn't in 1994. And he slept in the van that he went back and fourth to school in.
He was known to use that van for field trips and one can only presume he cleaned it out before he did that.
He wasn't carting his family round in that van. There was a family car that Margaret,Arawa and David used.

wasnt DB sleeping in there at

wasnt DB sleeping in there at one point Mike?

I read Don Mathias' blog

I read Don Mathias' blog entry. Seems light weight and poorly reasoned. He has made the same mistake Binnie made - looked at the footprint evidence and drawn bizarre conclusions.  I looked him up and he is a criminal lawyer practising in Auckland. He has a PhD in criminal law.

This is an example of the problem I have with academic legal beagles. They are obviously intelligent but often lack common sense and good judgment. Michael Reed is an example. Obviously a smart man but how can he continue to profess DB's innocence? He knows the facts - intimately - and yet he persists in drawing incredulous conclusions from the circumstantial evidence.

Much as I dislike and distrust the Jury system - I think a judgment made by ones peers trumps an academic opinion. In my mind we have two wrong judgments in the Bain case. The Jury acquittal and now the Binnie report.

Well the key was still in the

Well the key was still in the triger lock when police arived and the other key was still on the necklace in the jacket inside the van so its for sure the spare key from the pottery jar was used.

Aha, as I suspected.  Do you

Aha, as I suspected.  Do you think that Robin knew that the primary key was in the van where he was sleeping?

The primary key

Kent, I believe the primary key was left in the van while David went for his mid-winter swim on the day before the murders -- Robin had transported him to the beach. This van was found parked at the side of the house. Robin spent the night in the caravan at the back of the house.

as i suspect db had it all

as i suspect db had it all well planned out including making sure it was in the jacket. i wonder what happened to his notebook.




how do we know that DB didnt

How do we know that DB didnt sleep in the van that night and RB was inside? is this also heresay evidence by DB? Does anyone remember the chasie lounge with a blanket on it from evidence pictures

Good idea with the

Good idea with the calculator.

My initial thoughts

Regarding footprints, I would have thought that the bloodied sockprints would point to David. The fact that Robin Bain was wearing unbloodied socks and shoes would put him i the clear on this item. Unless anyone buys the implausable idea that Robin Bain showered and changes his clothes (and shoes and socks). No pile of bloodied laundry was found in bathroom (Robin would have had no reason to hide it).

Bloody clothing

We know the green jersey the killer wore had blood on it because of weave marks from that jersey found in blood on door jambs, etc. And there would have had to have been at least one very bloody sock in the wash.
David said he didn't notice that any of the clothing in the washbasket had blood on them even though he left a bloody palmprint on the washing machine.
He said he seperated the coloureds from the whites but there were a couple of light coloured shirts in the washing machine plus three white socks and I bet that one of those socks was that very bloody sock.
I don't remember anyone suggesting that Robin had had a shower.  Karam reckons he rinsed his hands but didn't wash them properly and that is why he had blood smears on his hand which he said came from wearing those bloody gloves.
And we know the killer wasn't wearing shoes because of that bloody sockprint.

Robin's full bladder

Can anyone tell me where the toilets were located in the house and whether there was a risk that Robin would have discovered the bodies whilst relieving himself that morning? David had to rely on his father going straight into the lounge to kneel and pray on a full bladder whilst David concealed himself in the alcove which I find a bit strange as we all have to answer a call of nature first before doing our activities in the morning.

If you check the floor plan

If you check the floor plan of the house you will see the toilet is on the lower floor and Robin could have used it without discovering Arawa's body (or the other bodies) on his way to the front room where his body was found.

Robin was 58 and had 400 ml in his bladder. This is a normal overnight collection. Men with prostate problems can have a large volume of residual urine in their bladder (sometimes 1 - 2 litres) which remains in their bladder at all times and they only pass "overflow" urine. There is no evidence from the postmortem that this was the case with Robin. Of course Karam got maximum mileage out of this "possibility". A urologist said that a man with prostate problems "can have up to 3 litres in his bladder"  This mischievous evidence effectively shut down further speculation about Robin's bladder contents.

It seems far fetched to postulate Robin got up , executed his family and then shot himself - and not had a pee!. Possible but highly unlikely.

I think Robin would have relieved himself as soon as he got up - or at least within a few minutes. This raises the possibility of him either being woken by David with the rifle and "escorted" to the lounge or being accosted by David when he walked in the front door after retrieving the paper from the gate.

The long and the short of it is that the "full bladder" evidence is contestable -- along with just about every other piece of evidence in this confounding case. This has been Karam's modus operandi from the outset --- Find an element of doubt in every significant item of evidence and fully exploit that doubt. Frustrating for the prosecution but very effective for the Bain defence team! 

Re:your comments

Yes the full bladder is probably a red herring. I don't suppose there was a toilet or bucket in the caravan which Robin might have used? I don't subscribe to the theory that David threatened Robin with a gun at the threshold as he would not want to risk a struggle with his father in which the gun was dischaged. I think the early morning prayer routine on the bean bag had probably been going on for years and David relied on it to take Robin off guard with just the one shot,the position of the magazine placed on its head and the spent cartridge case in the alcove being the giveaway that David was the perpetrator and not Robin,along with the rifle not being in the right place and all the other forensic evidence (including no connection whatsoever of Robin's clothing with Stephen).

Not so

Not all men have to go to the toilet before commencing their morning's activities.
I quite often don't have any need to go, though I do go because the toilet is handy [en suite]  and  I know I am going to have to go sooner or later.
The toilet was downstairs. If Robin came in the back door the toilet was adjacent.
But the fact is he was in the lounge and he had not been to the toilet, so if he had felt the need to go he would have gone before going up the stairs.
If he entered the house via the front door then he would have gone downstairs to the toilet before going into the lounge, had he felt the need to go to the toilet.
The toilet was not near any of the bedrooms.
However it would have been very unlikely for Robin Bain to have not gone to the toilet either before or after he supposedly shot four members of his family, one of them after a struggle. It is very unlikely that he could have carried out all that activity on a full bladder. 400ml is a normal overnight collection . I have checked that out myself.  


Robin Bain would only have prayed in the lounge a maximum of four mornings a week because he did not return home from Tuesday through to Friday afternoon.
David would have known his routine for those days.
It would appear Robin Bain was shot from the computer alcove because the shell from the bullet that killed him was found in the alcove.  It is not known what position he was in when he was shot but an ESR scientist said he was most likely upright.