April Jones trial: Bone fragments from 'human skull'
Bone fragments found in the fireplace of a man accused of killing five-year-old April Jones were from a human skull, a jury was told.
A bone analysis specialist told Mold Crown Court the skull had been put in the fire "as fragments". A fragment was also found in the bath waste pipe.
Mark Bridger, 47, of Ceinws, Powys, denies abducting and murdering April, who went missing near her Machynlleth home on 1 October 2012.
He claims he accidentally ran her over.
The court has been told he did not know how he disposed of her body because he was suffering memory loss caused by alcohol and panic.
The prosecution claims he murdered April after abducting her while she was playing near her home on the Bryn-Y-Gog estate.
On Tuesday, forensic anthropologist Dr Julie Roberts explained that her role was to examine material recovered from the fireplace in the living room at Mr Bridger's home.
She said the five fragments recovered from the fire were subjected to a range of tests but not all fragments underwent every test partly because they were very small.
She said she was asked to consider three questions:
- Are the fragments burnt bone?
- Where are the fragments from in the skeleton?
- Are the fragments human or non-human?
The fragments were all burnt bone, she concluded, and "four of the fragments can be assigned to the cranium and one we can't say one way or the other".
Giving evidence about fragment A, Dr Roberts said there were "several specific features" which were unique to human skull.
The fragment was compared with an archaeological specimen of a skull belonging to a child aged about four to eight years old.
Dr Roberts said: "I was confident that this was a piece of human cranial bone."
Fragment A was selected for DNA analysis but it was not possible to obtain a DNA profile from the sample because it was so badly burned, she said.
It was compared to bones from 14 other different species at the School of Veterinary Medicine in Liverpool including dog, fox, cat, ferret, squirrel, chicken, pig, horse, goat and sheep.
Dr Roberts said that because of the impact this type of evidence had on the case and the family "we wanted to be absolutely certain" before drawing any conclusions.
A second fragment, called C, was also said to feature the characteristics of a human skull and was, in Dr Roberts's opinion, consistent with a "younger individual".
"It's burnt to a sufficiently high temperature whereby all the organic material has gone, so it's completely combusted," said Dr Roberts.
Analysis on another fragment showed it to be compatible with human bone but it was not possible to tell on a fourth fragment, she said.
Dr Roberts said that in her experience of cremations, she would have expected to find other remains if a whole skull had been burnt. These would include facial bones and particularly traces of tooth, she said.
She said that "in other words I think those fragments have been put in as fragments".
She agreed what was found could have been part of a "clean-up process" at the property but said it was not the only possible interpretation.
For the defence, Brendan Kelly QC cast doubt on Dr Roberts's conclusions and said one internationally-renowned expert in the field, Professor Susan Black, disputed the prosecution's findings.
Prof Black was contacted by the Crown Prosecution Service last year to compile a report but Mr Kelly said she had disagreed with what other experts were saying.
Mr Kelly said: "She has no confidence at all that what was found in the fireplace was human bone, does she?"
Dr Roberts: "She doesn't appear to."
Mr Kelly went on to say that Prof Black was "even less confident" that they were the remnants of a human child.
Later, the jury heard evidence from another expert in the analysis of human remains, forensic anthropologist Linda Ainscough, who said she had searched through a quantity of ash and found 16 bone fragments, 12 of which were "very, very small".
She said she was confident they were "consistent with being bone" and had all been burnt but it was not possible to tell whether they were human or non-human.
Of the smaller fragments, she said two appeared more cranial than non-cranial, six appeared "post cranial" - everything aside from the head - and it was not possible to say where in the skeleton the other four might have come from.
Regarding the five samples from the fireplace, she agreed with the conclusions of Dr Roberts.
She said she had been asked to examine 22 separate exhibits which included traps from beneath sinks and the bath at Mr Bridger's property.
She said she examined the bath waste pipe and recovered an "incredibly small" fragment measuring about 3mm x 2mm which had the appearance of bone which had come from the cranium.
The jury heard from two other experts who analysed the fragments found.
Prof Holger Schutkowski said the bone was consistent with the human skull and evidence hinted towards it coming from a child.
The jury also heard from Prof Christina Cattaneo, a Milan-based forensic pathologist and anthropologist who works on burnt and cremated remains especially related to cases of organised crime in Italy.
She said in her opinion the fragments she analysed were from a human being.
Anthropology expert Prof Susan Black for the defence said she initially thought the fragments she examined were bone but "could not confirm human or non-human origin".
She said she would need "definitive evidence to be able to make an opinion".
Prof Black called into question some of Prof Schutkowski's findings and said there was no scientific evidence to conclude that one of the fragments had come from a juvenile skull.
Asked her opinion of some of the expert evidence heard earlier, she said she had described it as "confirmation bias" which involved finding evidence that "fundamentally supports what you're saying".
Questioned about one of the pieces of bone she said: "I have no idea what it could be. I have not seen anything like that in a human skeleton. I can't help you."
However, she said she agreed the samples were burned bone.
The court has previously heard that blood found in several locations around the defendant's house matched April's DNA.
The case has been adjourned until Wednesday, when Mr Bridger's defence is due to start.
April's disappearance sparked the biggest police search in UK history. She has never been found.
As well as abduction and murder, Mr Bridger also denies intending to pervert the course of justice.