Ambulance and police officers gave evidence at the High Court in Christchurch on Monday about David Bain's behaviour in the hours after the dead bodies of his family were found.
Mr Bain, 36, is being re-tried over the murders of his parents, Robin and Margaret, and siblings Arawa, Laniet and Stephen at the family's home in June 1994.
The defence says Robin Bain killed the others in the house in Every Street, before shooting himself.
Terry Van Turnhout, a police constable assigned to observe David Bain that morning, said he seemed to be in shock. He said when Mr Bain was taken to the station, he asked if he would be held up for long because he was rehearsing for a play.
The defence has argued that Mr Bain was suffering from post-traumatic stress.
Earlier, an ambulance officer told the jury he did not think David Bain's seizure after his family's bodies were found was genuine.
Ray Anderson was the first ambulance officer to give Mr Bain medical care at the scene, and said he saw Mr Bain shaking. He told the court he had seen people shake in that manner before, but only people who were trying to convince paramedics that they had a medical condition when they did not.
A second ambulance officer who was present that morning, John Dick, told the court he stayed with David Bain in the family home for two and a half hours. During that time, he said, Mr Bain remained in a foetal position.
At one stage he whispered that "black hands" were coming for him, although Mr Dick had to ask Mr Bain to repeat what he was saying several times, as he was speaking so quietly.
On Monday, the High Court retrial before a jury of seven women and five men heard its fifth day of evidence. The trial is expected to last at least 11 more weeks.
