Soham murder suspect Ian Huntley tried to comfort the father of Holly Wells after she vanished with Jessica Chapman, the Old Bailey has heard.
The girls disappeared last year
In a statement Kevin Wells said Mr Huntley, who denies the girls' murder, told him: "Kevin I'm so sorry, I didn't realise it was your daughter."
The court also heard Holly's mother Nicola describe her "desperate" wait for news of the 10-year-olds.
The girls disappeared from the town in Cambridgeshire, in August last year.
The former caretaker's ex-girlfriend, Maxine Carr, 26, denies attempting to pervert the course of justice and helping an offender.
On Wednesday Holly and Jessica's teacher, Joy Pederson, became the first witness to take the stand.
She described the girls as "loyal friends" who "would have stuck up for each other".
Mr Wells' description of his encounter with Mr Huntley, 29, came as the court was read statements from Holly and Jessica's parents - who are not expected to take the stand.
Holly's father said Mr Huntley had offered his words of sympathy after a news conference appealing for information.
Mr Wells said he had replied: "I know. Thank you for your kind words."
Mr Huntley said he needed to speak to the police to change his timings and had looked "drained, with panda eyes", the statement added.
The men had also met on the night Holly and Jessica vanished, when a search of the Soham Village College took place, Mr Wells said.
In her statement, Mrs Wells said she had "started to panic" when the girls missed a curfew.
She became increasingly concerned when she phoned Jessica's parents and the girls were not there.
"I was getting desperate. I was waiting for news which didn't come."
She waited up all night hoping for some news as searches continued.
Mrs Wells added she had not even been aware of Mr Huntley's existence until she saw him approach her husband.
Ian Huntley had met Jessica's mother, the court heard
But Mrs Wells said she had seen Ms Carr, hug her daughter at a majorette practice.
'Afraid of the dark'
Jessica's mother Sharon said she had met Mr Huntley as many as four times previously.
She worked at a playschool with Ms Carr and Mr Huntley, the statement said.
Mrs Chapman, a learning skills assistant, said Ms Carr had helped her daughter with homework and Jessica thought she was "cool".
She said her daughter was afraid of the dark and would sleep with her curtains open with a hall light left on.
Holly and Jessica's teacher, Mrs Pederson, said she would have recommended both girls be made house captains.
She said Ms Carr had tended to focus her attentions on a group of pupils including the girls and that she had been "gutted" not to get a job as a permanent classroom assistant.
Mr Huntley, who had been too ill to be in court last Thursday and Friday, was back in the dock with Ms Carr as the first of the statements were read out.
Mobile phone expert Peter Bristowe told the jury Jessica's mobile had "deregistered" from the network at 1846 BST, either because the phone had been switched off or the battery had failed.
Earlier this week jurors visited important sites in Soham and the spot where the girls bodies were found on 17 August 2002 - 13 days after they went missing.
The prosecution had already outlined its case against Mr Huntley and Ms Carr.