Here's what we know about the gunman who took hostages in Sydney

Police have named an Iranian refugee convicted of sexual assault and infamous for sending hate letters to parents of dead Australian soldiers as the gunman who took at least 13 hostages in a downtown Sydney chocolate cafe on Monday, according to multiple reports.

Police sources told The Sydney Morning Herald, The Australian newspaper, the BBC and other sources that Man Haron Monis, 50, is the gunman who took an unknown number of hostages in a Sydney cafe Sunday morning. Police said that Monis was killed when police stormed the cafe where he was holding the hostages early Tuesday morning.

The situation has sparked fears of a possible broader terrorist threat in the country, as well as concerns that other rogues will answer ISIS calls to action around the globe.

Monis, a self-described Iranian cleric who was granted asylum in Australia, was painted in the reports as a man well-known to Australian authorities. He moved to Australia in 1996 after he was granted political asylum, according to The Australian. He has a broad criminal record, but no reported or known ties to organized terror or extremist groups.

In October he was charged with 40 counts of indecent and sexual assault, including 22 counts of aggravated sexual assault and 14 counts of aggravated indecent assault. He was also charged last year as an accessory to the murder of his ex-wife, the mother of their two children.

But his history with Australian authorities dates back years — to when Monis started sending what are described as “grossly offensive” letters to the families of at least seven dead Australian soldiers killed in the coalition-led war in Afghanistan.

He described the soldiers as murderers and killers; in one letter he wrote that one of the soldiers would go to hell. Monis was sentenced to 300 hours of community service for sending the letters through the Australian postal service, but he was unapologetic. He said afterwards that he would hand-deliver his “flowers of advice.”

A website in Monis’ name — which was taken down Monday after police fingered him as the gunman — likens him to WikiLeaks co-founder Julian Assange, and says he is “not a member of any organization or party.” On the website, he also condemned coalition-led airstrikes against ISIS, saying “America and its allies including Australia” have engaged in “terrorism.”

Monis entered the Sydney cafe early Monday morning brandishing a sawed-off shotgun and wearing a bandana inscribed with Arabic language, according to The Australian.

The gunman reportedly forced hostages to hold up an Islamic flag at the cafe’s window, one that experts said was similar to the one brandished by al-Qaeda and Jabhat Al-Nusra, an al-Qaeda affiliate fighting the regime of Syrian President Bashar al-Assad in Syria.

But the flag is slightly different than that of the group calling itself the Islamic State, which is also known as ISIS or ISIL. An ISIS spokesman gave a speech in September in which he urged “lone-wolf” attacks from sympathizers in Australia, according to the SITE Intelligence Group, which monitors and tracks extremist groups in the Middle East.

Australian Prime Minister Tony Abbott has not called the situation a terrorist attack, but said there are “indications” that it could be “politically motivated.”

“We don’t know the motivation of the perpetrator,” he said in a press conference. “We don’t know whether this is politically motivated, though obviously there are some indications that it could be.”

Updated with latest information available.

Brett LoGiurato is the senior national political correspondent at Fusion, where he covers all things 2016. He’ll give you everything you need to know about politics, with a healthy side of puns.