Thirty-six minutes after the first emergency call came in, police had the alleged shooter behind yesterday's terror attack in custody, the Police Commissioner has confirmed.
The commissioner has given the latest updates on the Christchurch mosque shootings in a multi-agency media conference today.
Mr Bush said police were not searching for anyone that is an immediate threat after yesterday's terror attack on two mosques in central Christchurch, "but that doesn't mean that doesn't exist".
"I have no intelligence about current imminent threats, but I would never assume anything in this situation, which is why it is so important that we resource the intelligence and investigations phase of this, to make sure we understand everything and understand it urgently."
He said police took 36 minutes from the time a call was received yesterday to have the offender in custody.
"We were also on scene at the mosques way earlier than that. That was the time from the initial incident until we had the offender in custody.
The man was held in police custody and transferred to the court for his hearing.
He said he was "very happy" to hear the prime minister's comments this morning that there will be a change in the gun law.
Mr Bush also spoke of the close relationship between the Australian and New Zealand intelligence agencies.
"Our people are working very closely, as is the intelligence agencies.
"At this stage... this person was not known to us... was not a person of interest to either jurisdiction".
The vehicle that the offender was in contained a device that caused concerns and the Defence Force was used to render this safe, he said.
"This is a very wide reaching investigation, we are speaking to a considerable amount of people."
The commissioner said the top priorities for police included public safety in Christchurch and nationally; making sure the victims "get every piece of support they need to get them through this time"; that the responders involved in the events got support and that intelligence is gathered.
One offender, a 28-year-old man, has been charged with one count of murder and remanded to the High Court for 5 April, he said.
"I want to reassure the community that we have heroes that come to work every day to keep them safe," Canterbury District Commander Superintendent John Price said.
City Councillor Deon Swiggs spoke on behalf of the mayor and said the focus for the city was on victim support.
"We are working with those families and those victims to make sure they have the right support."
People wishing to lay flowers could do so outside the Botanic Garderns, he said.
A Civil Defence centre has been set up at Hagley Park to support families and police.
Deborah Strokes of Victim Support said the organisation has been working hard to put in place robust support systems that will start to be implemented from tomorrow.
Forty-nine people were killed and 42 are in hospital after the shootings at the Al Noor Mosque on Deans Ave in Riccarton and the Linwood mosque.
Dozens more police are being deployed to Christchurch and there is a heightened police presence around the country, including at mosques and community events.