When gardaí told one of the two boys accused of Ana Kriegel's murder that her blood was found on his boots he replied, "are you joking me" and asked: "Are you actually being serious about this?" the Central Criminal Court has heard.
Gardaí put it to the boy that the only way he could have Ana's blood on his boots was if he was in the room when she was assaulted and asked him if he was in that room. He replied: "No."
Boy A also told gardaí in interview that his interests included "anatomy, the human body" and the "inner life, the skeleton".
The accused, who are 14, cannot be named because they are minors. They have each pleaded not guilty to murdering the 14-year-old Kildare schoolgirl at Glenwood House, Laraghcon, Clonee Road, Lucan on May 14 last year.
Boy A is further charged with the 14-year-old’s aggravated sexual assault in a manner that involved serious violence to her. He has pleaded not guilty to that count also.
Detective Garda Marcus Roantree told Brendan Grehan SC for the prosecution that Boy A, his father and a solicitor came to Clondalkin Garda Station on May 24, 2018.
Det Gda Roantree formally arrested Boy A at 8.07am that morning on suspicion of Ana's murder.
He told Mr Grehan he was satisfied that Boy A understood the caution given to him before his interview and said gardaí went to great lengths to explain everything to him.
Detective Garda Tomas Doyle told Gerardine Small BL for the prosecution that he interviewed Boy A six times at Clondalkin Garda Station in the presence of the boy's father and a solicitor.
In the first interview Boy A's solicitor put on record his objection to the fact that material he had sought from gardaí was not made available and he was therefore unable to properly advise Boy A and his family.
Gardaí began by explaining to Boy A the definition of murder. When asked if he understood the difference between right and wrong he said "leaving the door open for somebody" would be an example of right. He added: "Tripping somebody up is wrong."
He agreed that taking a bar of chocolate without permission would be wrong. He explained the difference between truth and lies by saying: "Truth is if you tell somebody what happened. A lie is if you don't tell somebody what happened."
Gardaí told Boy A that they were only interested in truth and wouldn't tell him any lies.
Boy A told gardaí that his interests include "anatomy, the human body". He explained that he was interested in the "inner life, the skeleton". When gardaí asked if he was interested in drawing live people he replied: "No, more evolutionary."
He said his friends were not interested in that kind of thing.
Garda Doyle then read a statement Boy A had previously made in which he said he was attacked by two men in the park on the same day that Ana went missing. He said he suffered injuries including to his arms, back and legs after being grabbed from behind, knocked to the ground and kicked.
In his second interview on May 24 Boy A told gardaí that he had met Ana in the park on May 14 but said he was not with her in the lead up to to the time when she was reported missing by her parents that evening.
Gardaí then showed Boy A CCTV footage from that day. Boy A identified himself and Boy B in footage taken from private CCTV outside a house at 4.11pm. Boy A said he had a bandage on his arm from a fall some weeks previously.
On another piece of CCTV footage taken nearby that evening Boy A said he could see two males and added: "They look like the lads that beat me up on that day." He asked for gardaí to zoom in but they were unable to do so.
Having viewed more footage he said: "That might be good news. I think that might be one of the males that beat me up. Is there any more footage?"
Gardaí then showed him footage of a male and female walking nearby on the same evening. He told them the female could be Ana Kriegel but then added that he didn't remember Ana having white patches on her leg. He then agreed with gardaí when they suggested it was Ana.
Gardaí showed him footage taken at 4.58pm that evening which they said showed a male with a backpack not wearing gloves. At 17.05pm they said a male with a backpack could be seen wearing gloves. Boy A said he could see that.
They asked him if he thought they were the same person and he replied: "Do you think it's the same backpack?" Boy A's solicitor then expressed a concern.
Before Boy A left with his solicitor the garda told him: "Just to answer your question I do think it's the same backpack."
When Boy A returned Garda Doyle put it to him that forensic analysis showed Ana's blood was on his boots. He replied: "Are you joking me?" Garda Doyle replied: "No."
The boy said: "Are you actually being serious about this?" He asked to be allowed out to get air. His solicitor asked him if he was going to be sick and he was given a glass of water.
The interview continued with Garda Doyle saying: "I want to be clear, this is significant and serious." Boy A replied: "I'm aware."
Gardaí then showed Boy A some Tescon branded tape and asked him if he had ever been in possession of tape like that. "No," he replied. He was then shown a black hoodie and said he thought Ana was wearing "something like that" when he met her on May 14.
Gardaí said they believe the CCTV footage showed that the route Boy A told gardaí he took on that day was not correct.
They also said that Ana's blood was on his boots and asked him if there was anything else he wanted to tell them that would help their investigation.
"No, there's nothing else," he replied.
The garda continued: "What I'm saying to you is the only place you could have got the blood on your boots was in that room so were you in that room?"
"No," he replied. The garda then asked him if what he said in his earlier statement on May 15 was the truth and he replied: "Yes. That's the truth."
Garda Doyle said gardaí had searched his home and found a backpack. Gardaí showed a photo of the backpack to Boy A and asked him if he had that bag with him in the park at any stage on the day he met Ana. He said he did not.
He also denied that the male in the footage he was shown earlier on CCTV was him.
Scientist John Hoade of Forensic Science Ireland earlier told Mr Grehan that blood on both of Boy A's boots matched that of Ana Kriegel. He added that the blood pattern indicated that: "[Boy A] either assaulted Anastasia Kriegel or was in very close proximity to Anastasia Kriegel when she was assaulted."
The scientist also examined a 92cm long by 4cm by 3cm stick with a nail or staple in both ends that gardaí found near Ana's body.
Showing the stick to the jury he pointed out that it was charred on one end and had blood stains along it with heavy blood staining on the charred end. This was, he said, transfer blood staining which results from contact with a blood bearing surface.
He described another area of blood staining as "percussive" explaining that such stains are caused when there is already blood on the stick and it is swung, impacting on a surface.
The DNA from that blood matched Anastasia Kriegel's, he said. He added that the stains he saw on the stick were what he would expect to see if it was used as a weapon in the assault on Anastasia Kriegel.
Mr Hoade also identified for the jury a section of a nine inch concrete block which, he said, was taken from the scene.
He agreed with Mr Grehan that it was heavy and awkward and would require two hands to manipulate. He noted blood stains on all six sides of the block but told Mr Grehan he did not sample those stains.
When Mr Grehan asked why, he said it was his understanding that, "there was no suggestion the block was used as a weapon in the assault."
The trial continues in front of Justice Paul McDermott and a jury of eight men and four women.