Murder accused Kieran Greene was late on his school run with his young sons the morning after he allegedly killed their grandmother Patricia O'Connor, the Central Criminal Court heard.
The primary school secretary said Mr Greene was a "lovely parent" and she "didn't get any indication of anything whatsoever off him" when he dropped his children off that day.
The jury also heard a garda noted he seemed "nervous and edgy" when the family were being spoken to one morning while Ms O'Connor, his partner's mother, was still missing.
Evidence for the prosecution was continuing in the joint trial of Mr Greene (34) and three other people charged over Ms O'Connor's death in 2017.
Patricia's daughter Louise O'Connor (41), her ex-partner Keith Johnston (41) and their daughter Stephanie O'Connor (22) are accused of impeding the investigation.
They all deny the charges.
Patricia O'Connor (61), a grandmother-of-seven, was allegedly murdered on May 29, 2017, at the house at Mountain View Park, Rathfarnham, she shared with family including Louise, Stephanie and Mr Greene.
Her dismembered remains were found in 15 parts, scattered in the Dublin and Wicklow mountains between June 10 and 14, that year. She died from blunt force trauma to the head caused by at least three blows from a solid implement.
The secretary at Mr Greene's sons' school told the court gardaí asked on June 15, 2017, to view CCTV and were particularly interested in footage from May 30.
This showed Mr Greene arriving with his children at 9.18am and leaving at 9.21am that day. He used the front door as the side entrance was closed after 9.10am and he was not on time.
The secretary agreed with prosecutor Roisin Lacey SC that Mr Greene spoke to her at the hatch and she "didn't get any indication of anything whatsoever off him".
In cross-examination, she told Conor Devally SC, for Mr Greene: "He was a lovely parent, a very good parent."
Garda Padraic Syron said he went to the house at Mountain View Park on the morning of June 12, 2017, to follow up missing person enquiries about Patricia O'Connor.
Kieran Greene sat on the couch with three family members.
The garda asked the people there about Patricia O'Connor and was told nobody had heard from her.
"I did note during the conversation he seemed extremely nervous and edgy," the garda said.
The trial continues.