Man Haron Monis was a deluded man seeking attention, experts say. Source: DailyTelegraph

Man Haron Monis was all those things and more, but why exactly he took 17 people hostage inside a busy Sydney cafe with a gun and a fake bomb strapped to his chest, we may never know.

What we do know is that Monis was a loner with a very troubled past.

According to terrorism expert Professor Greg Barton, Monis acted like a “lone wolf terrorist”, and was clearly also someone who struggled to fit into society.

The Monash University professor said Monis was shunned in both Shia and Sunni circles.

He also said much like Norwegian mass killer Anders Breivik, Monis saw himself as a man on a mission, serving some sort of delusional purpose.

Man Haron Monis and his girlfriend Amirah Droudis were charged in connection with the murder of his ex-wife. Source: News Limited

“Anders Breivik was a strange individual who saw himself as part of a larger community, but who lived with his mum and was a loner,” Prof Barton said.

While admitting Monis wasn’t part of an organised terror network as such, Prof Barton said he probably saw himself as one in his own mind.

“He’s not a network player, he’s a lone player,” he said.

Prof Barton also said while it was difficult for him to diagnose Monis as a sociopath, he appeared to have a severe narcissistic disorder.

He added while terrorists weren’t all defined by mental illness, groups such as ISIS were seeking to exploit foreign fighters or supporters who were vulnerable, troubled and were looking for a purpose.

“Monis seemed driven by a desire for attention and to be in the spotlight,” he said.

“Breivik saw himself acting in a strange defence of Europe, Monis saw himself acting in the interests of the caliphate.

Man Haron Monis sent offensive letters to families of dead Diggers. Source: News Limited

However Queensland University of Technology criminologist Associate Professor Mark Lauchs said it was important the siege wasn’t elevated to a “terrorist attack” as such.

Assoc Prof Lauchs said Monis was simply a deranged person running a hostage situation adding that if Monis wanted to kill on the scale Breivik did, he would have acted much earlier rather than draw out a long hostage situation.

“This wasn’t a political act,” he said.

“I don’t think he even knew what he wanted. A terrorist act is usually defined as having a political purpose and extortion, he simply wanted attention.

“This incident was not about religion and neither was it a terrorist attack, but given that perception by the paraphernalia Monis used.”

He added he didn’t think Monis intended to die either and had no connection with IS other than in his own head.

Anders Behring Breivik confessed to a bombing and mass shooting that killed 77 people on July 22, 2011. Source: Supplied

Even his own lawyer admits he never found anywhere or group to fit into.

Manny Conditsis said his client was an “intensely conflicted and contradictory person.”

“He was a loner who had never found anywhere to fit in since he arrived on that flight from Iran,” he told the Herald Sun.

“He was on the fringe of the fringe. No community had accepted him, not the Iranians, not the Muslims.”

Experts agree he acted alone and wasn’t part of an organised terrorist group, despite proclaiming support for IS.

At the time of the siege Monis was on bail after being charged with accessory to the murder of his ex-wife Noleen Hayson Pal.

The 30-year-old died in the stairwell outside his unit in Werrington in Sydney’s west last year after she returned to collect their two children, then aged seven and four following a custody visit.

Monis’s then-girlfriend, Amirah Droudis, 35, was charged with murder and both she and Monis were freed on bail in December last year.