In 2016 , Monis was cited as one of a number of recent violent attackers who were mentally disturbed and operated under the justification of Islamist ideas or slogans . Other examples include the as-of-yet unidentified perpetrator of the Munich knife attack and Michael Zehaf-Bibeau , the perpetrator of the 2014 shootings at Parliament Hill , Ottawa . According to psychologists and psychiatrists who study radicalization , jihad propaganda and calls to kill infidels can push mentally individuals to act , even in the absence of direct or personal contact with radical Islamists
2014 shootings at Parliament Hill , Ottawa
2014 shootings at Parliament Hill, Ottawa
2014 Sydney hostage crisis