DNA from a bone found in Sunshine Coast bushland matched that of Daniel Morcombe’s mother and two brothers, a court has been told.
Brett Peter Cowan, 44, is standing trial in the Supreme Court in Brisbane charged with murdering the 13-year-old schoolboy more than a decade ago.
On Wednesday, the court heard SES volunteers found an initial bone on August 20, 2011, while a cluster of bone fragments was found a short time later near Coochin Creek, in the Sunshine Coast hinterland.
University of Adelaide researcher Dr Jeremy Austin told the jury he received a humerus (upper arm bone) for testing on August 23, 2011.
Under questioning by Crown Prosecutor Glen Cash, Dr Austin said mitochondrial DNA testing was used because mitochondrial DNA – inherited from the mother only – survived longer in degraded samples.
“The mitochondrial DNA profile from the bone sample was a hundred per cent matched to Denise Morcombe and to Denise’s other sons Dean and Bradley Morcombe but the mitochondrial sequence from the bone did not match Bruce Morcombe, the father of Daniel Morcombe,” he said.
“It’s exactly the result we expect if the bones had come from a son of Denise Morcombe because the mitochondrial DNA is inherited from your mother and not from your father.”
Forensic pathologist Dr Peter Ellis conducted an autopsy on the 17 bones or bone fragments found and said they belonged to a “young growing human” in their early teens.
A photo of the bones laid out on a table was shown to the jury and included parts of a left and right upper arm bone, parts of a pelvis, segments of both lower leg bones and some vertebrae from the lower back.
“The surface of the bones themselves were fairly dry. They were as you would expect bones that have been the ground for quite some time,” Dr Ellis told the court.
“Some of them showed very small marks … what one could describe as scratches … from my observation they looked either more like the marks of an animal’s teeth, possibly even of the efforts of the excavating.”
Daniel disappeared in December 2003 while waiting for a bus at Woombye, in the Sunshine Coast hinterland.
Cowan, 44, has pleaded not guilty to murder, indecent treatment of a child, and interfering with a corpse.
The trial continues.