To add to that, are we also assuming it was from the coffee cup they retrieved DNA?
I’m surprised the DNA wasn’t damaged by either, fire, smoke or water used to put the fire out.
I'm also surprised that an organic plant, a fair amount of paperwork, clothes, and various other items didn't go up in flames.
If you took an exact replica mock version of Joy's relatively small flat and then started 2 fires in 2 different rooms, and then walked out and left it, it would have taken just over 5 minutes or so for the fires to have completely engulfed the entire flat. And that's without any accelerant.
So if we treble the time to around 15 minutes, it would then have undoubtedly incinerated everything in the flat, because the sheer pressure and heat combined would have caused automatic combustion of everything in the flat; that is even without the need for the actual flames to touch anything.
And yet the video footage taken after the fire doesn't support that.
So we know by the science that if the fire service entered the flat some time around 23.30pm (at the very EARLIEST based on the initial 999 call at 23.18pm that lasted just over 2 and a half minutes, a response time of around 4 minutes and the need to ascend up to the 6th floor and secure lower floors first) then we know that the fire couldn't have been started much before 23.15pm, possibly 23.10pm at the very extreme end of the possible start time of the fire.
And so when we consider that the only man who appears to visibly see the flames and therefore know about the fire, then makes a 999 call at 23.18pm, then we know that the fire must have been started before 23.18pm.
And if the fire service burst into the flat no earlier than 23.30pm, and the fire hadn't completed incinerated everything that SHOULD have been destroyed by the fire, then we can be virtually certain that the fire couldn't have been raging for any longer than 15 minutes, because that's around triple the required time needed for a fire to do so.
And if the fire couldn't have been started before 23.15pm, then the man who makes the call sees the flames just a couple of minutes after the fire has started. This is because he would have needed to have parked his car, go out, and then gone into the phone box to make the 999 call.
That means he sees the fire no later than 23.17pm.
But when we add the tantalising clue that a heavy man was heard running down the stairwell, and then a black male well over 6ft tall was seen running from the building and was nearly hit by a passing motorist, then the timing of the fire being started at 23.15pm to a black male making a 999 call just 3 minutes later, ties in perfectly with the sequence above.
What we must realise is that times and descriptions given by witnesses can often be wrong and therefore unintentionally misleading to an investigation. On that basis, we must use the definitive parameters to construct the correct framework for the case.
In this case, we know the 999 call was made at 23.18pm, and so the fire had to have been started BEFORE 23.18pm
We also know that the man who made the call was a black male
And based on the science, we know that the fire couldn't have been started much before 23.15pm, because by the time the fire service entered that flat, the evidence simply doesn't support the idea that the fire was started before 23.00pm, because there's no way that a multiple fires in a flat could rage for 30 minutes, and yet most of the flat survives fire damage, including some items that would have been combustible under extreme heat and pressure.
So with all that in mind, it supports the theory that the man who made the 999 call was the man who started those fires.
But of course, if he wasn't, then how peculiar is it that nobody else from the flats called 999?
There were 3 other flats on Joy's floor and yet the first person to call 999 was a man driving past in his car outside.
Crucially, I don't believe for a moment that the man who made that call could actually see those flames. He just knew about the fire, and didn't want to be a mass murderer and so needed to alert emergency services so that other residents didn't die as well.
It also explains why he never came forward of course.
Interestingly, without that CCTV image of the white male entering the flat at 22.31pm, it would seem to me that the man who made the call was also the killer; as is emphasised and implied by the original 1996 broadcast. However, in the 2015 update broadcast, the man who was seen running out the building and who nearly got hit by the car is for some reason never mentioned; eluding to him having been ruled out.
However, it makes me wonder why the CCTV photo hadn't been mentioned earlier?
It would seem to me that the original investigative team were either unaware of the CCTV image, had it but chose to keep it quiet, or had it but didn't understand its relevance at the time of the 1996 broadcast.
It does seem rather odd; almost as though the CCTV image wasn't something the original investigative team wanted to pursue for whatever reason?
Of course, with the sudden emergence of the CCTV image made public in 2015, the idea that there were possibly 2 different men involved then gains some traction.
IMO the man on the CCTV image was the killer, but he left around 15 minutes before the fires were started, giving him time to get away and create an alibi. He then tells the other man to wait and start the fires, which the 2nd man does just before he is then heard running down the stairs, avoiding being hit by the car, and then making the 999 call.
The issue with that of course is; how did the 2nd man enter Joy's flat if the killer had already left?
Well it's likely that he was already in the flat with the killer, and they BOTH drank coffee.
Failing that, the 2nd man may have arrived after the killer had left, and if the flat door was open, he could have just walked in.
If the door was closed however, then the 2nd man needed to have had a key somehow.
Lots of variables but when we work from the basic facts first and then branch outwards, we can slowly build a picture of what may have occurred on that fateful night.