The question of whether Oscar Pistorius (OP) knew he was shooting at his girlfriend Reeva Steenkamp (RS) behind the toilet door, should hinge on whether he can convince the court that he was unaware that his girlfriend had left the bedroom and gone to the toilet.

Using probability mathematics, the likelihood that he was genuinely unaware that RS had gone to the toilet can be estimated.

I will try to get the probability from what I estimate reasonable people would do or notice.


OP said that he woke up approx 3am and found RS awake in the bed next to him and they exchange a couple of words with her before he got out of bed to bring in a couple of fans from the balcony without ever leaving the bedroom.

Assuming that OP was standing at least one foot from the balcony door, this would mean he was most likely only between 1 or 2 ft from his bed as when (according to him) RS up and went to the bathroom without him noticing that she had got out of bed and gone to toilet.

OP says he was on his stumps and that the fans were on whilst he was bringing them through the door.

For the purposes of simplification, some of OP explanation to try and make his story more credible should be explored and either accepted or dismissed at this point.

First his assertion that the fans were on as he brought them into bedroom:

What are the chances that OP on his stumps can balance (or even attempt to balance) on his stumps whilst lifting in a large fan that is running?
I will guess if there were 20 disable people asked this question it would be fair to say that no more than 1 of the 20 may attempt to carry a heavy fan that is on whilst stretching and balancing on the stumps

1/20 = 0.05 so I would assume the chances that OP actually was bringing the fans in is so improbable.

OP's other mitigation was that after bringing the fans in, he drew the curtains shut and the room became pitch black presumably to explain why he couldn't see that RS was not in bed or see her get up out of bed in his peripheral vision.

It is reasonable to assume then that RS only got up to go to the bathroom after OP had already brought the fans in and drawn the curtains making the room pitch black.

So from time OP finished drawing the curtain, picking up RS's shorts to cover light from the stereo and him hearing (according to him) the window in the bathroom slide open could not have been more than 20 second.

The probability that of all the time RV would choose to get up and go to the toilet was in the 20 second window when the room was pitch black can be so improbable as to be dismissed.

How many able -hearing people standing 2 foot from a bed would not hear somebody getting out of bed?

not hear the person pass within 3 feet of you?

Ask 100 able people this and my guess is that no more than 1 person in 100 may fail to hear somebody get out of bed and walk past them within 3 ft.

So probability that OP did not hear Reeva go to the toilet in 1/100 = 0.01

The probability that OP did not see RS get up out of bed and walk within 3 ft of where he was standing even in his peripheral vision can be estimated.

Asking 100 people of able eye-sight perhaps only 4 out of 100 would fail to see somebody in their peripheral vision walk within 3 ft of them.

So probability of OP not seeing Reeva get out of bed and walk past within 3ft of him is 4/100 = 0.04

The probability that OP failed to notice that nobody was on the bed whilst he was reaching under the bed to retrieve his gun.

may be 1 person in 1000 may fail to see that or notice that there was nobody in a bed that they were touching in order to to reach under it.

probability OP was unaware that RS was not in bed at this point is 1/1000 = 0.001

The probability that OP did not question whether RS was still in the bed when she did not respond to him telling her to phone the police as he walked towards the bathroom with the gun.

Perhaps only 1 person in a 1000 would proceed to confront a potential armed robber without ensuring that his partner is aware what is going on.

=1/1000 = 0.001

The probability that OP remained unaware that his girlfriend was behind the bathroom after 2 of his first 3 shots shattered her hip bone and smashed her arm can be assumed to be the same probability that a person receiving such devastating injuries would not cry out in pain.

I am estimating that 1 person in a million may stay silent after receiving 2 non-fatal gunshots

= 1/1000000 = 0.000001

So calculating the final probability that OP was unaware that he was shooting at RS in the toilet you multiply all the probabilities together

= 0.01 x 0.04 x 0.001 x 0.001 x 0.000001

=0.0000000000000004

= approximately zero chance that OP was unaware that his girlfriend was in the bathroom as he was shooting her.

This is to say that only 1 person in 2,500 Trillion people would have been unaware that their girlfriend was behind the toilet door.

Oscar Pistorius just got away with cold-blooded murder.