Police forensic staff stand outside a supermarket in Auckland, New Zealand, Saturday, Sept. 4, 2021. New Zealand authorities say they shot and killed a violent extremist, Friday Sept. 3, after he entered a supermarket and stabbed and injured six shoppers. Prime Minister Jacinda Ardern described Friday's incident as a terror attack. (AP Photo/Brett Phibbs)

WELLINGTON, New Zealand (AP) — New Zealand authorities imprisoned a man inspired by the Islamic State group for three years after catching him with a hunting knife and extremist videos — but at a certain point, despite grave fears he would attack others, they say they could do nothing more to keep him behind bars.

So for 53 days from July, police tracked the man's every move, an operation that involved some 30 officers working around the clock. Their fears were borne out Friday when he walked into an Auckland supermarket, grabbed a kitchen knife from a store shelf and stabbed five people, critically injuring three.

Two more shoppers were injured in the melee. On Saturday, three of the victims remained hospitalized in critical condition and three more were in stable or moderate conditions. The seventh person was recovering at home. The youngest victim was a 29-year-old woman, the oldest a 77-year-old man.

Court documents named the attacker as 32-year-old Ahamed Aathil Mohamed Samsudeen, a Tamil Muslim from Sri Lanka who arrived in New Zealand 10 years ago on a student visa seeking refugee status, which he was granted in 2013.

Undercover officers monitoring Samsudeen from just outside the supermarket sprang into action when they saw shoppers running and heard shouting, police said, and shot him dead within a couple of minutes of him beginning his attack. A bystander's video records the sound of 10 shots being fired in rapid succession.

The attack has highlighted deficiencies in New Zealand's anti-terror laws, which experts say are too focused on punishing actions and inadequate for dealing with plots before they are carried out. Prime Minister Jacinda Ardern said lawmakers were close to filling some of those legislative holes when the attack occurred. She vowed law changes by the end of the month.

Police Commissioner Andrew Coster said the law they were working under required a suspect to make the first move.

“We might have an understanding of intent, and ideology, and we might have high levels of concern,” Coster said. “But that is not sufficient for us to take any enforcement action.”

Samsudeen was first noticed by police in 2016 when he started posting support for terror attacks and violent extremism on Facebook.

Police twice confronted him but he kept on posting. In 2017, they arrested him at Auckland Airport. He was headed for Syria, authorities say, presumably to join the Islamic State insurgency. Police searches found he had a hunting knife and some banned propaganda material, and he was later released on bail. In 2018, he bought another knife, and police found two Islamic State videos.

He spent the next three years in jail after pleading guilty to various crimes and for breaching bail. On new charges in May, a jury found Samsudeen guilty on two counts of possessing objectionable videos, both of which showed Islamic State group imagery, including the group’s flag and a man in a black balaclava holding a semi-automatic weapon.

However, the videos didn’t show violent murders like some Islamic State videos and weren’t classified as the worst kind of illicit material. High Court Judge Sally Fitzgerald described the contents as religious hymns sung in Arabic. She said the videos described obtaining martyrdom on the battlefield by being killed for God’s cause.

A court report warned Samsudeen had the motivation and means to commit violent acts in the community and posed a high risk. It described him as harboring extreme attitudes, living an isolated lifestyle, and having a sense of entitlement.

But the judge decided to release him, sentencing him to a year’s supervision at an Auckland mosque, where a leader had confirmed his willingness to help and support Samsudeen on his release.

The judge said she rejected arguments Samsudeen had simply stumbled on the videos and was trying to improve his Arabic. She said an aggravating factor was that he was on bail for earlier, similar offenses and had tried to delete his internet browser history.

Fitzgerald noted the extreme concerns of police, saying she didn’t know if they were right, but “I sincerely hope they are not.”

The judge also banned Samsudeen from owning any devices that could access the internet, unless approved in writing by a probation officer, and ordered that he provide access to any social media accounts he held.

“I am of the view that the risk of you reoffending in a similar way to the charges upon which you were convicted remains high,” the judge concluded. “Your rehabilitation is accordingly key.”

Two months later, Samsudeen took a train from a mosque in the Auckland suburb of Glen Eden where he was living to a Countdown supermarket in New Lynn, tailed at a distance by police. He wheeled a shopping cart around the store like the other customers for about 10 minutes. The store was less crowded than normal due to coronavirus distancing requirements, and undercover police were hanging back so as not to be noticed.

At about 2:40 p.m. he began shouting “Allahu akbar” — meaning “God is great” — and started stabbing random shoppers, sending people running and screaming, unleashing an attack that shocked a nation.

On Saturday, Samsudeen's brother Aroos said the family wanted to send their love and support to everyone hurt in the attack. He said Samsudeen had been suffering from mental health problems, wanted to impress his friends on Facebook and had no support.

“He would hang up the phone on us when we told him to forget about all the issues he was obsessed with. Then he would call us back again himself when he realized he was wrong,” Aroos said. “Aathil was wrong again yesterday. Of course we feel very sad he could not be saved.”

News from © The Associated Press, 2021