Ana Kriégel's blood was found on a backpack, mask, gloves and knee-pads seized in a search of the home of one of the boys accused of her murder, the Central Criminal Court has been told.
Two fourteen year old boys deny murdering the schoolgirl in a derelict house in Lucan on May 14th 2018. The first accused boy also denies violently sexually assaulting her.
Gardai searched the home of the first accused boy in this case on May 24th 2018, after his arrest on suspicion of murder.
The Central Criminal Court heard gardai were told to conduct the search discreetly and sensitively, to use hire cars instead of garda cars and not to wear clothes identifying them as gardai.
They were to use plastic bags instead of garda evidence bags.
They found a backpack in a wardrobe in the boy's room which contained a homemade mask, black gloves, knee pads, shin guards and a black neckwarmer.
Forensic scientist, John Hoade gave evidence of examining the items and they were shown to the jury.
The mask had holes for the eyes and nose, it stopped at the mouth and was jagged and painted red at the bottom.
The court heard Ana Kriégel's blood was found on the outside and inside of this mask.
There was a blood stain above the left eye. Mr Hoade said he examined the mask to see if he could find a DNA profile to determine who was wearing it.
He told the court DNA matching the school girl and matching boy A was found inside it around the nose and mouth areas.
Mr Hoade said Ana's blood was also found on the bag, on both black gloves and on the knee pads.
He told the court he examined a concrete block found at the scene which he had not previously tested.
Two areas of blood staining on this block also matched Ana Kriégel's DNA profile.
He said he examined clothes and runners received from the second accused boy in the case.
Mr Hoade said there was no blood found on the runners and only a small stain on the front of his hooded top, matching the boy's own DNA profile.
The court heard evidence from Dr Bríd McBride, also from Forensic Science Ireland, who examined a mark on the front of Ana Kriégel's hooded top and compared it with impressions made by the footwear worn by the two accused boys.
She said she could not rule out the possibility that the mark had been made by a boot worn by Boy A but there was insufficient detail. She ruled out the runners worn by Boy B as a source of the mark.
Forensic scientist, Dr Charlotte Murphy told the court that a male DNA profile found on part of the blue tape on the schoolgirl's body as well as male DNA found on a swab from Ana's neck matched that of boy A.
Defence counsel, Patrick Gageby, for Boy A, asked if "casual intimacy or kissing" might leave DNA.
Dr Murphy said it would depend on the nature of the contact, how long it lasted and whether there were any bodily fluids.
She said she could not determine how a DNA transfer had taken place.
She had been tasked with carrying out "male specific DNA profiling" to identify any male DNA on the samples she was given.
Nora Lee, a forensic scientist for more than 35 years, told the court the tape recovered from the ligature around Ms Kriégel's neck, was a similar type of tape to a roll of builder's tape found in a search of a shed at Boy B's home.
She said the ends did not fit together.
This could be because the roll was not the same roll used to form the ligature or another piece of tape had subsequently been removed from it.
Evidence in the case will continue on Monday.