Police say the man arrested in connection with the shotgun killing of two staff in a Work and Income office in Ashburton this morning may not be charged until tomorrow.
A woman staff member seriously wounded in the shooting is in Christchurch Hospital, but has been able to talk.
The Canterbury District Commander, Superintendent Gary Knowles, said the suspect - 48-year-old Russell John Tully - was found on a rural property just south of Ashburton about 5.30pm.
Mr Tully suffered minor dog bites when he was apprehended and Gary Knowles said Mr Tully was to be examined by a doctor before being interviewed at the Ashburton police station tonight.
He said the police were still searching for the weapon involved and information was scant.
Trespass order against Mr Tully
The Social Development Ministry's chief executive, Brendan Boyle, told Checkpoint the office had a trespass order against Mr Tully after some intimidating and threatening behaviour in the last couple of weeks.
"He hadn't been violent but he'd been threatening."
"He had been involved with the office ... like on and off for a period of time," Mr Boyle said.
Mr Boyle said security at the office had not been beefed up.
He said about seven people worked at the office. Mr Boyle said the injured woman has been able to talk, and had asked for privacy.
Mr Boyle wouldn't be drawn on the full details of what happened in the Work and Income office, until the police finished their investigation.
But he said staff at the office acted incredibly bravely, if not heroically during the day.
Huge manhunt for suspect
Armed police swamped the town following the killings, which occurred at about 10am. At one stage they focused on the Ashburton River bed area, about four blocks from the scene of the shooting.
They raided at least one house in the town and later focused on the Lake Hood subdivision outside the town, where the arrest was made.
Residents were advised to take precautions and stay indoors while the suspect was on the loose. He was believed to have been carrying a sawn off shotgun.
A witness, Daniel Suckling, was in his office across the road from Work and Income when the shooting happened.
He told Checkpoint what he saw immediately afterwards.
"There was this man on the footpath outside who was giving this continuous stream of abuse and obscenities to a man who was calmly unchaining his bike."
Mr Tully had been struggling to find accommodation in the town and had been living in a tent in the local domain before this morning's shootings.
Ashburton mayor Angus McKay said Mr Tully approached him for the first time six weeks ago about help with finding somewhere to live. He said he put the man onto the appropriate provider and that was the end of the conversation.
"That would be a month ago. He did say that he had a house he could go to in Timaru, but he wanted to stay in Ashburton."
Angus McKay said he was in shock when he heard the police wanted to speak to Mr Tully about today's shootings.
- Just after 10am on Monday a gun was discharged at the Ashburton Work and Income office.
- The man fled on a bike and police issued an alert for Russell John Tully.
- About 11am police said two people were dead and one was seriously injured.
- Ashburton residents were told to stay indoors and police swarmed the region.
- Work and Income closed its offices in Ashburton, Christchurch, Timaru, Oamaru, Christchurch and Balclutha.
- Police raided at least one house in the town and later focused on the Lake Hood subdivision outside the town, where the arrest was made.
- Russell John Tully was found by police on a rural property south of Ashburton at about 5.30pm.
- Russell John Tully is taken to the Ashburton police station to be interviewed. Police say he may not be charged until tomorrow.