One of the boys accused of murdering Anastasia Kriegel told a friend that he thought his co-accused was trying to set him up and was a "snake in the grass", the Central Criminal Court has heard.
The witness, who cannot be identified because he is a minor, told prosecution counsel Brendan Grehan SC that Boy B described seeing Boy A getting Ana into a headlock and then onto the ground while Ana fought back by punching and kicking Boy A's arms and legs.
Another witness said he remembered Boy A as being "agitated and fidgety" following Ana's disappearance while Boy B was "calm and collected".
The accused, who are both 14, cannot be named because they are minors. They have each pleaded not guilty to murdering the 14-year-old schoolgirl at Glenwood House, Laraghcon, Clonee Road, Lucan on May 14 last year.
Boy A is further charged with Ana's aggravated sexual assault in a manner that involved serious violence to her. He has pleaded not guilty to that count also.
The jury heard today from five child witnesses. One of those told Mr Grehan that he would sometimes hang out with Ana and he remembered that on May 14, the day she went missing, she was "slagging me off because I'm short."
He remembered that the day after Ana went missing he was with a group of boys including Boy A and Boy B.
They were talking about Ana's disappearance when Boy A said he and Boy B were with Ana the previous day in the park. Boy B was in the room, he said, but he wasn't part of the conversation.
He said Boy A told the group that he got beaten up in the park by two teenagers and that he fought back. He remembered that Boy A was limping and had an injury to his arm.
That summer the witness was walking with Boy B when he asked Boy B what he thought about the "whole Ana thing". The witness said: "He said he had to tell me something and not to tell anybody else and I said, 'ok'."
He said Boy B told him that Boy A asked him to bring Ana to the park. He said he and Ana met Boy A at the abandoned house and that Ana and Boy A "started to get into a physical kind of argument and it got more violent as time went on."
He continued: "He said Boy A got Ana into a headlock and tried to get her on to the ground and at this point [Boy B] ran away."
Retelling what he remembered, the witness said Boy B described how Boy A and Ana went into the abandoned house and he saw them "start to get into a small scuffle or fight and then he saw [Boy A] get her into a headlock and try to get her onto the ground. He got freaked out and ran away."
He said Boy B described Ana as fighting back, trying to push Boy A and punch him and kick him in the arms and leg.
Under cross examination, the witness told Mr Damien Colgan SC for Boy B that Boy B told him Boy A was "trying to get behind his back and be a snake in the grass, to set him up."
He said Boy B thought Boy A had set him up by asking him to call for Ana. He said Boy B told him not to say anything about it and he didn't tell gardai what Boy B had told him until the following November. It didn't really come to his mind before that, he said, and he "kind of forgot about it".
Another child witness told Mr Grehan that he remembered speaking with both accused in a group of children after Ana had gone missing but before her body was found on May 17.
He said Boys A and B said they were the last two people with Ana in the park. He remembered that Boy B left the group and then Boy A told him that after he left Ana in the park he was "jumped on" by two 20-year-olds.
He said Boy A didn't seem himself that day. He was "agitated and more aware and fidgety."
Boy B, he said, was, "just fine, just like every day. The way he always was, calm and collected."
Another child witness told Mr Grehan that he joined a pledge for a "satanic cult" in September of 2017 after Boy B asked him to.
He said Boy B wanted to see how many signatures he could get as a "challenge". He added: "It wasn't serious." After about two to three days they forgot about it, he said.
Under cross examination, the witness told Mr Colgan for Boy B that the Satanic cult was a "joke".
Another child told Mr Grehan that he remembered Boy B approaching him to ask him if he wanted to be part of his "cult".
He said the rules were that you weren't allowed to talk about God, you could only talk about Satan and you had to share your homework. He said the only part he really noticed was the bit about homework and so he said yes.
He said he believed Boy B was the leader of the cult but he said after being asked to join he never thought about the cult again.
Under cross examination, he told Mr Colgan that nobody took the cult seriously, adding: "We said yes and that was the end of it. There was no more mention of it."
A female child witness told Mr Grehan that "everyone knew" that Ana liked Boy A but she wasn't sure if Ana ever said it directly to him. She said Ana asked her to find out if Boy A liked her but the witness said: "I don't think he liked her."
The trial continues in front of Justice Paul McDermott and a jury of eight men and four women.