The Auckland supermarket terrorist assaulted prison officers and threw excrement at them during his time in New Zealand's jails.
Ahamed Aathill Mohamed Samsudeen, who injured seven people in his stabbing attack on Friday, was so hostile while in custody he was moved to the same unit that houses the Christchurch Mosques terrorist.
On Tuesday, NZ's corrections department released a lengthy statement on Samsudeen's time in prison.
He was housed at Mt Eden Corrections Facility for two stretches between May 2017 and July 2020.
In June 2020, he assaulted two officers and was moved to the maximum-security Auckland Prison and placed in the Persons of Extreme Risk Directorate unit.
That unit also houses Brenton Tarrant, the Australian terrorist who killed 51 worshippers in attacks on two Christchurch Mosques in 2019.
It is unclear whether Samsudeen came across Tarrant, who is housed in isolation.
Corrections National Commissioner Rachel Leota said Samsudeen was "very, very difficult" to manage and was "openly hostile and abusive" to officers.
"His behaviour was non-compliant, with multiple incidents of threats and abuse toward staff, including numerous incidents of throwing urine and faeces at staff, threatening the use of violence, and assaulting staff," she said.
In the June 2020 incident, he struck corrections officers after an argument about which exercise yard he was allowed to use.
Samsudeen then spent a year in the maximum security prison before his release in July, committing his act of terror seven weeks after his return to the community.
Many are questioning the 32-year-old's pathway to radicalisation and levels of care while in the community.
From July, Samsudeen was living in an apartment at Masjid e Bilal, a mosque in a neighbouring suburb to the New Lynn supermarket where he committed his atrocity.
New Zealand Muslim Association president Ikhlaq Kashkari told Radio NZ the community wanted to help but did not feel prepared to help rehabilitate him.
"I'm upset because, what if we'd done things properly? Would this have been avoided?" Mr Kashkari said.
"I have no idea how on earth they managed to talk this small Islamic centre ... to take him on board.
"If I was to have a cynical view of it I would say they wanted to get rid of him."
Samsudeen was subject to a 24-hour police surveillance operation on his release which involved up to 30 officers at a time.
Clarke Jones, an Australian National University criminologist who assessed Samsudeen in 2018, wrote in the Guardian that police eschewed intervention programs that might have stopped his path to radicalisation.
"Police opted for a different approach ... choosing surveillance and monitoring over rehabilitation," he wrote.
"Samsudeen showed clear signs of depression and post-traumatic stress.
"My advice to the courts at the time was that his trauma needed to be urgently addressed ... left untreated, he would continue to feel alone and struggle with recurring feelings of anxiety, fear and worthlessness.
"As it was, law enforcement treated him exclusively as a violent extremist, with no apparent efforts to address his mental health issues."
Ms Leota said Samsudeen resisted all involvement in Corrections' mental health programs and did not meaningfully engage with a Muslim leader brought in to assist.
"We worked closely with police and partner agencies to carry out extensive planning to keep the community, and our staff, safe from the extreme risk that his violent extremist ideology presented," Ms Leota said.
Ms Leota said she was proud of the efforts of her staff to care for Samsudeen.
"We will always ask what more could have been done to prevent the horrific offending that occurred on Friday," she said.