He said he heard Williams state, “Do you reckon it was worth it?”, and he repeated it again, before reminding him he was under caution.
Sgt James Cox, who was custody sergeant at Parkside police station in Cambridge when Williams was arrested, gave evidence in person to the jury.
The court heard Williams was “treated as a vulnerable adult” and he authorised him to be supported by an appropriate adult.
Jurors heard Williams had officers constantly on watch.
Running Sgt Cox through the detention log, Gillian Jones KC, representing Williams, said: “It was reported to you that [Williams] suffers from psychosis, wasn’t it.”
Cox replied: “I believe so, yes.”
The barrister said: “It was reported to you that he took medication.”
Cox again replied: “I believe so, yes.”
He said it was his assessment Williams “didn’t appear to be intoxicated”, and the court heard he was informed by escorting officers “Mr Williams suffered from schizophrenia”.
The court heard it was determined the detainee was not fit to be interviewed.
Jones said a note from a healthcare worker in custody logs read that Williams “appeared to be responding to voices”.
She told the court it said Williams “laughed”, agreed when asked if he was hearing any voices, and when asked what the voices were saying, “he smiled and said ‘lots of things'”.
Jurors have also seen CCTV footage of Williams punching an officer in the face in the early hours of 2 November, and heard he was observed to be “climbing on his toilet several times and stroking the air vent”.
The following afternoon, a forensic psychiatrist advised he observed “active psychotic symptoms”.
The court heard Williams was never interviewed about the allegations.