DUNEDIN, New Zealand — The gun enthusiast with light brown hair and an Australian accent did not stand out among the 100 or so members of the Bruce Rifle Club, who practiced shooting at a range in a forest in southern New Zealand.
The enthusiast, Brenton Harrison Tarrant, favored a bolt-action hunting rifle and an AR-15 semiautomatic rifle and would participate in shooting competitions, said Scott Williams, the club’s vice president. But no one saw any warning signs.
“He was polite. He would help put things away. He would help set up,” Mr. Williams said. “He worked like a Trojan.”
New Zealand officials are now wondering if they missed something about Mr. Tarrant, a 28-year-old Australian citizen who lived in Dunedin and is the suspect in the shootings at two mosques in Christchurch on Friday that left at least 50 people dead.
On Monday, Prime Minister Jacinda Ardern said she had ordered an inquiry into whether government agencies could have prevented the attack.
“The purpose of this inquiry is to look at what all relevant agencies knew — or could or should have known — about the individual and his activities, including his access to weapons,” she said at a news conference in Wellington, the capital.
She also said her cabinet had agreed “in principle” to an overhaul of the country’s gun laws and was working out the details.
“Within 10 days of this horrific act of terrorism, we will have announced reforms that I believe will have made our community safer,” Ms. Ardern said.
Earlier, Wally Haumaha, the deputy New Zealand police commissioner, said identification specialists had worked through the night to identify the people killed at the Al Noor and Linwood mosques so that their bodies could be returned to their families. Islamic leaders and victims’ relatives have been discussing whether to hold a burial for all 50 victims at once, possibly on Wednesday.
As of Monday night, 31 people were hospitalized in Christchurch, nine of them in critical condition. A 4-year-old was in critical condition at a hospital in Auckland, where she was flown after the attack.
Police investigations continued, as counterterrorism officers in Australia searched the homes of Mr. Tarrant’s mother and sister in the northeastern coastal towns of Lawrence and Sandy Beach.
And in New Zealand, more than half a dozen police officers searched Mr. Tarrant’s residence near the center of Dunedin, about 220 miles south of Christchurch. The blue-gray house had air-conditioning units, wide, rectangular windows with open curtains, an overgrown yard and a mailbox with a sticker reading: “NO JUNK MAIL. Thank you!”
Two weeks before the attack, Mr. Tarrant’s one-bedroom, one-bathroom home was listed online as available for rent starting April 2, according to a cached version of the post that has since expired.
President Recep Tayyip Erdogan of Turkey said Monday that Mr. Tarrant made two trips to the country in 2016, one for three days and the other for 43 days. Turkish officials said they were investigating what he did there.
Few details have emerged about Mr. Tarrant’s life. It is unclear whether he had a job. Several neighbors said they did not know many of their neighbors and had not met Mr. Tarrant.
Anytime Fitness confirmed in a statement on Monday that Mr. Tarrant was a member of the Dunedin branch of the 24-hour gym. On Sunday, several regulars at the gym said they did not know Mr. Tarrant or recall seeing him there.
What is known is that Mr. Tarrant was a licensed gun owner and member of the Bruce Rifle Club. He appeared to already have shooting skills when he joined in February 2018 and he typically went to the range by himself, said Mr. Williams, the club’s vice president.
The club has come under criticism from a former member of the New Zealand military named Pete Breidahl, who said he reported it to the police in 2017 after visiting in November that year. He said he had had concerns about the mental stability of the members and the way they handled firearms.
“They wore cammo around the range, like they were living some military base fantasy,” Mr. Breidahl said in an interview on Monday.
Mr. Breidahl said that he had been in contact with the police after the Christchurch shootings and that he was scheduled to meet with them on Tuesday.
Mr. Williams said that the Bruce Rifle Club was cooperating with the police investigation and that it was closed until further notice.
By the time Mr. Tarrant joined the club, he had already started buying firearms from Gun City, one of New Zealand’s largest gun retailers. David Tipple, the managing director, said his company had sold Mr. Tarrant four firearms along with ammunition between December 2017 — a month after Mr. Tarrant received his gun license — and March 2018.
Mr. Tipple said Mr. Tarrant’s online purchases had not raised any red flags.
“He was a brand-new purchaser, with a brand-new license,” he said.
Darren Jacobs, chief executive of Hunting & Fishing New Zealand, confirmed on Monday that the retailer’s Dunedin branch had sold Mr. Tarrant a bolt-action hunting rifle in 2017.
Still a mystery is the source of a semiautomatic rifle that can be seen in a video of the attack on Al Noor Mosque. Mr. Tipple said it did not come from Gun City.
The details of Mr. Tarrant’s arsenal emerged as New Zealand considers tightening its gun regulations. Among the legislative changes the prime minister is likely to consider are a ban on semiautomatic weapons and laws requiring that all firearms be registered and all gun sales recorded.
Mr. Tipple said that New Zealand should avoid “emotional responses” in the debate over gun laws.
“This man wrote in his manifesto that the purpose of using a firearm was to divide us,” Mr. Tipple said. “If we allow him to make changes in our ideology and in our behavior, he’s won.”
Others disagreed. Outside the Dunedin branch of Gun City on Monday, Karen Nielsen, 47, stood holding a white poster board with black capital letters reading, “This store sells weapons of mass destruction.” She had a solemn expression on her face as she described how the “horrific, horrific events” in Christchurch had inspired her to protest that morning after she drove her children to school.
Ms. Nielsen said that as a former hunter, she was not opposed to guns. Her husband used to be a member of the Bruce Rifle Club like Mr. Tarrant.
“There’s nothing wrong with single-bolt firearm rifles,” she said. “It’s the semiautomatics that we need to get rid of. If you can’t kill an animal with one shot, you shouldn’t be hunting.”
As she was speaking, Brett Cleveland left the store holding a bag with ammunition that he had just purchased. Mr. Cleveland listened calmly, then said that he owned an AR-15 and was also a member of the Bruce Rifle Club.
“As far as I am aware, there is only one rifle club in this area,” Mr. Cleveland said. “He had to go there. It wasn’t like he joined up because he went, ‘There is a bunch of like-minded people.’”
He said he hoped that government officials would find a way to compromise.
“The knee-jerk reaction is going to be the gun people aren’t going to want any changes,” Mr. Cleveland said. “The other people are going to want a ban on everything. There is never any common sense. The middle is usually the best place to be.”
Trade Me, New Zealand’s biggest online marketplace, said on Monday that it had removed all semiautomatic firearms and related parts from its site in response to customer concerns.
Also on Monday, a teenager charged with creating and distributing objectionable materials made his first appearance in a Christchurch court. Prosecutors say the 18-year-old, whose name and identifying details have been suppressed, published a photo of Al Noor Mosque with the message “Target acquired” a week before the shootings. He did not enter a plea and was remanded into custody until his next court appearance in April.
The police said that they did not believe he was involved in the attack.