A policeman who met Ian Huntley five days after Holly Wells and Jessica Chapman vanished said that the caretaker had "a great sense of guilt".
The Old Bailey has heard Pc Tim Cleary was flagged down by Huntley at about 1am on Thursday August 8 last year when he drove into Soham Village College.
Pc Cleary has stated Huntley asked him how the investigation was going and then invited him into his house for a cup of tea, telling him to be quiet as his partner was asleep upstairs.
Asked how Huntley behaved in general, Pc Cleary said: "He was very upset, he looked very tired and I spent quite a long time reassuring him that I am sure there was nothing more he could do.
"He came across as having a great sense of guilt, that he could have done more when he met the children."
The court has already heard that Huntley said he saw the girls on the evening of Sunday August 4 and may have been the last person to see them.
Pc Cleary also revealed that the topic turned to the subject of other cases including that of Milly Dowler, who was still missing and Sarah Payne.
The witness said: "We talked about Milly Dowler that nobody at the time had been discovered and where the police may be going with that investigation."
Asked what Huntley was saying about this, the officer added: "He was suggesting it may be some time before bodies were found."