Mr Ian Huntley, the man accused of murdering schoolgirls Holly Wells and Jessica Chapman, wept and told a detective "You think I have done it", London's Old Bailey heard today.
Detective Constable Jonathan Taylor said Mr Huntley had broken down in front of him two days after he had gone to his house to take a statement.
"Huntley said to me: 'You think I have done it. I was the last person to see them and speak to them.' He started to cry," Det Taylor told the court.
"I told him not to persecute himself and to pull himself together. I told him that other people had seen the girls in the area that night and that seemed to cheer him up a little bit."
Mr Huntley, a caretaker at Soham College where the girls went to school,denies murdering the 10-year-olds in August 2002. Prosecutors say his girlfriend, 26-year-old teaching assistant Ms Maxine Carr, conspired to cover up the crime.
Assistant caretaker Mr Michael Gee, who gave evidence earlier, told the jury he went into Mr Huntley's house two days later and saw Ms Carr scrubbing the kitchen tiles hard with a scourer.
"She was complaining that the tile paint was coming off because she was scrubbing so hard," he said.
The jury has already heard from the prosecution that the girls, last seen wearing matching red Manchester United football tops, died in Mr Huntley's house, probably from asphyxiation.
Their burned and decomposed bodies were found by chance after two weeks, side by side in a remote drainage ditch near Lakenheath in Suffolk, eastern England, about 15 miles from the village of Soham.