A man pulled a woman from her car and held a gun to her head before fleeing in her car yesterday afternoon.
He then crashed into a second car and pointed his gun at the head of its driver before being shot by police.
Assistant Commissioner Richard Chambers said support was being offered to both motorists, who had described the ordeal as one of the worst days of their lives.
The Auckland chase started when the Eagle helicopter spotted a white BMW that had been stolen from the Youth Garage car yard, being driven erratically.
Chambers said the driver of the BMW crashed into a car waiting at an intersection.
"The offender got out and approached the driver waiting patiently at the lights, and held the firearm at that person's head."
Police shot at the man, who fled in the bystander's car, running over her foot as he left.
Police pursued the man but he soon crashed into another car.
"Again we saw the offender holding a firearm to the head of a member of the public," Chambers said.
Police shot and injured the gunman, allowing the member of the public to escape.
Officers then gave first aid to the offender, who was taken to hospital in a serious but stable condition.
"My staff have done a remarkable job today and I acknowledge the courage they showed," said Chambers at a press conference this afternoon.
He said those who were involved in the shooting were not from the specialist armed offenders' squad.
"They've done a remarkable job today to take [on] someone presenting a real risk to members of the community."
He described the events as "volatile, high-risk and dangerous".
"Police staff make every effort to make sure members of the public are safe, we are safe. At a busy place like an intersection that is a challenge but my staff have done very well today."
Chambers said the man at the centre of yesterday's shooting had been a "person of interest" and wanted by police "for some time".
He appealed for footage from bystanders to help with the investigations.
Chambers said staff were looking for another person who may have been involved in stealing the BMW from the yard.
Hamilton shooting
Chambers updated details about the shooting in Hamilton last night.
Police went to an address in Hillcrest at 7.50pm, concerned for the safety of a man who had a high-powered weapon, he said.
The man wasn't at the initial address, but when he returned he opened fire on police, Chambers said.
Police shot him and he died a short time later.
Chambers revealed a police officer was injured, after falling and striking his head.
He underwent surgery yesterday.
Chambers said the man who died was from Hamilton.
Police had been concerned he was going to use the high-powered weapon against people.
"Sadly, as a result of what occurred last night, he lost his life," said Chambers, adding his staff had done their best to save him.
Chambers said the dead man had fired on police at least five times.
Independent Police Conduct Authority investigations are under way into both shootings, he said.
Chambers said the situation in both Auckland and Hamilton had been traumatic for police.
Earlier report: Auckland shooting
One person was seriously hurt and another has moderate injuries after witnesses on Church St East in Penrose reported hearing gunshots before 11am yesterday.
Witnesses have described seeing a "largely built man" speed through Ellerslie in a white BMW X5 with no plates, before it crashed into a kerb on Great South Rd in Penrose.
The man leapt from the BMW and ran straight towards a motorist waiting at the nearby traffic lights, a witness called Steve said.
Pointing his pistol at the female driver, he then pulled her out of the car, said Steve, who didn't wish to give his last name.
The woman appeared to kneel on the ground with her hands on her head as the man carjacked her Suzuki and threw a "wild" U-turn before speeding towards a State Highway 1 on-ramp.
Police had their weapons trained on the man but appeared unwilling to fire with innocent bystanders nearby, Steve said.
"You have to admire their bravery," he said.
"They didn't shoot, which is a good thing given how tightly packed cars are at that intersection."
A worker at Youth Garage said two people had been involved in the theft of the BMW.
"A lady came in first, tried to be like a customer, checking around," Dali Hou said.
"Then she came back again, checking cars again. I think about that time she stole our key and then she went out again and a guy came over and just drove it out … yeah, teamwork."
Hou wasn't at the car yard when the theft happened but had spoken to the yard's director who had tried to stop the man leaving in the BMW, and had to move to avoid being struck.
No weapons were presented by either the man or woman, Hou said. He had been told they were aged in their 30s or 40s.
The car was taken when the director went to get some information from inside.
"When he came out, they were going."
The car, a 2013 or 2014 BMW S5 was "nothing special", Hou said.
"It's just kind of cheap. We have for $14,800."
The director of the yard, who was nearly run over as the couple departed - with the man driving - was okay.
"He never saw a weapon."
Two intersections on Great South Rd in Penrose remain closed.
One at Great South Rd and Church St/South Eastern Highway, and another at Great South Rd and Campbell Rd, said Auckland Transport.
Another witness called Sonia also reported seeing a man with a firearm running down Great South Rd, weaving in between cars.
The man pointed his weapon back at the three pursuing officers, who were shouting at him to stop, said Sonia, who didn't wish to give her last name.
"He was pointing a firearm at the cops and trying to run. I could hear them shouting but my window was up and I needed to get out of there."
Another witness said he saw a white BMW X5 with no plates speed through Ellerslie, "travelling 100km/h in a 50km zone".
The BMW then hit a kerb at speed, at which point it "caught air", the witness said.
The car's airbags deployed and police were able to capture a "large-build man", who had been driving, the witness said.
Unconfirmed reports allege the BMW may have been stolen from a dealership.
St John said they were called at 10.59am.
One person was seriously hurt and taken to Auckland Hospital, while a second patient was taken to Middlemore Hospital with moderate injuries, a spokesman said.
Sonia saw the police chase while pulling up to the lights at the Z petrol station on Great South Rd.
The man appeared to be holding a pistol, she said.
She was worried the man with a firearm might run through the petrol station.
Her first thought had been to "get out of there" and get home to her children, she said.
She also saw a number of cars U-turn from the area to try to get away. She also reversed away from the area and travelled home on an alternative route.
A cafe manager on Church St East said his customers were sitting outside when they heard gunshots.
They didn't see what happened, the cafe manager said.
But after hearing the shots they went onto the road and saw a swarm of police cars about 150m further down on Great South Rd.
A worker near the Church St intersection told the Herald she heard sirens and a number of police cars "swoop in".
She also saw an ambulance and a helicopter.