[7] Monis variously promoted himself as an Iranian intelligence official, a political activist, a spiritual healer and expert in black magic, an outlaw bikie and a Muslim cleric.

[8] He told a psychiatrist who diagnosed him with schizophrenia that he had to change his name for "security reasons," variously calling himself "Michael Hayson Mavros",[9] "Sheikh Haron",[10] and "Ayatollah Mohammed Manteghi Boroujerdi".

[8][11] Monis ran a "spiritual healing" business, telling some women that they needed to submit to sexual molestation to receive treatment.

In the 1990s, Monis ran a company called Salehan-ë Amal (Persian: صالحان عمل), which he used to buy discounted tyres from the Iranian government and re-sell them on the black market.

[18] In 2001, using the pseudonym Ayatollah Manteghi Boroujerdi,[11] he claimed in an interview with ABC Radio National's The Religion Report that he had been involved with the Iranian ministry of intelligence and security, and that his criticism of the regime and secret information he possessed had resulted in his persecution as well as the detention of his wife and children.

[36] In 2009, in Granville, NSW, Monis gave a lecture calling for an Islamic society and taunting foreign governments saying, "your intelligence service is not working properly.

[12] In July 2011, Monis was charged at a St Mary's police station for intimidation of his ex-wife, following a confrontation in a McDonald's car park in Green Valley.

His ex-wife said that Monis had "intimidated, duped and emotionally manipulated her" and that around 2007 he "became more strict" and told her to wear a veil, and restricted her from "singing and dancing" allegedly telling her "I'm doing it for Islam ...

[42] Prosecutor Brian Royce said Monis' claims that the Iranian Secret Police and the Australian Security Intelligence Organisation (ASIO) were trying to frame him for the murder were fanciful.

[43] On 22 January 2014, Monis appeared at Parramatta Local Court and, after informing magistrate Joan Baptie that he was representing himself, began discussing documents that he claimed were held by ASIO.

Magistrate Baptie told Monis that she had no power to order the release of documents held by ASIO and "advised him to stop talking because he would harm his defence".

Monis staged a protest outside the court, following the adjournment of the case, "wearing chains and holding a sign claiming he has been tortured in custody".

[51] In an inquest held after Monis' death, Dr. Jonathan Phillips diagnosed him as showing mixed features of narcissistic and antisocial personality disorders.

According to Justice Dyson Heydon of the High Court, the letters compared "the (deceased soldier) son to a pig and to a dirty animal.

[58] In an inquest, lawyer Chris Murphy said that Monis claimed to be contacting families to recruit "people who had suffered loss in war" to join his cause.

[59] In December 2011, Monis appeared before the Court of Criminal Appeal in Sydney arguing that the charges against him were invalid because they infringed his implied constitutional freedom of political communication, but the three-judge panel unanimously dismissed his case.

[71][72] Monis ran a "spiritual healing" business and promoted himself as a clairvoyant and an expert in "astrology, numerology, meditation and black magic" services.

[73] Monis used the business to make unwelcome sexual advances toward vulnerable women, telling them that they could only receive treatment if they undressed and allowed him to massage their breasts and genitals.

On 14 March 2014, Monis was arrested and charged with sexually assaulting a young woman who went to his consultancy in Wentworthville, New South Wales, for "spiritual healing", after seeing an advertisement in a local newspaper.

Commercial news media in Sydney often condemned Monis for making videos with his girlfriend narrating, expressing happiness about the Holocaust and 9/11 and attacking rape victims.

[81] Monis attended Hizb ut-Tahrir rallies and was described by Sydney Morning Herald journalist Anne Davies as "a little unstable.

[17] On the day prior to taking a group of people hostage, Monis posted to his website: Islam is the religion of peace, that's why Muslims fight against the oppression and terrorism of USA and its allies including UK and Australia.

[22]Australian Muslim commentators said that his conversion to Sunni Islam was less out of genuine religious conviction than designed to provide credibility in seeking an association with ISIL, as one "can't really claim to love IS when you're a Shiite and they're trying to exterminate you".

It appears he came to espouse an extreme Islamist ideology on his own, and police and intelligence agencies have not identified any connections between Monis and international terrorist organisations.

[87] On the morning of 15 December 2014, Monis took hostage employees and customers at the Lindt chocolate café in Martin Place, Sydney, across from a Seven Network television studio.

Hostages were made to hold up a Black Standard with the shahādah (Islamic statement of faith) written in white Arabic text.

[88] Neighbouring buildings, including government offices and financial institutions, and Martin Place railway station, were evacuated and locked down.

[91][92] In a website posting prior to the hostage incident, Monis denied all the charges against him, calling them politically motivated,[6] accusing the Iranian Ministry of Intelligence and Australia's ASIO of framing him.

[94] In 2016, Monis was listed under mentally disturbed individuals who have launched recent violent attacks justified with Islamist ideas or slogans.

According to psychologists and psychiatrists who study radicalisation, jihad propaganda and calls to kill the infidels can push mentally ill individuals to act, even in the absence of direct or personal contact with Islamists.