OPINION: Seventeen people and their families and associates have been put through torment by Man Haron Monis. Two have died. It is a terrible tragedy that we all share. There will be investigations, inquests and inquiries in many agencies and forums, the details will be published and we will know how it happened. In the meantime, we grieve and ask why.

It has emerged that Monis was a disturbed man with a history of criminal activity who adventitiously latched onto the cause of IS. He died with allegations against him unresolved. Why was he in a position to be able to do as he did?

Some attention turns to the laws of bail in NSW. On  December 12, 2013, Monis was released on bail on a charge of being an accessory to the murder of his ex-wife. From that time (as reported) he was subject to conditions that included residence and daily reporting to police. On April 14 and 16 this year, he was refused bail on charges of sexual assault. On May 26, he was granted bail again with conditions reimposed.

There were no appeals against the bail orders and, it seems, no basis for police to be concerned to have the situation changed. Monis was due to appear next at court on February 27.

Charges of sending despicable letters to families of deceased Australian servicemen had been dealt with.

In 2012 the NSW Law Reform Commission conducted a thorough review of bail laws. In 2013 a new Bail Act was passed by both houses of Parliament with no dissent. It came into effect on May 20, 2014 (six days before Monis's re-release on bail). The significant change (for present purposes) was from a system of presumptions for and against bail depending on offence, to an overall test of unacceptable risk; that if released the accused would fail to appear, commit serious offences, endanger the safety of victims or others in the community or interfere with evidence.

Following a review between June 27 and August 5 this yar in response to media attention to three bail decisions, the government amended the act with changes to take effect from January 28. The basic tests for bail remain, but one relevant procedural change has been made. That is to require, including in cases of the kind faced by Monis, that the accused show cause why it would be unjustified for him to be remanded in custody.

It cannot be said with confidence that if Monis had been dealt with under the coming law, then he would have been remanded in custody and not free to wreak havoc. The police investigating him and the magistrates considering bail had all the relevant information available (as they do in thousands of cases every year). Decisions were properly made after careful consideration and in accordance with the law, based on that publicly available material. Nobody could divine what was taking shape deep within Monis's mind, much less act on it.

Mental disturbance is not a reason to imprison a person. Allegations of offending leave the accused with the presumption of innocence and the right to liberty – both principles we rightly take seriously in our society. Under the coming bail laws Monis may well have been able to discharge his onus on the information then presented to the court.

This atypical and aberrant case is certainly not a good basis for launching into yet more interference with the Bail Act. Laws cannot cater for every situation – that is why courts exercise judgment.

Nicholas Cowdery is Visiting Professorial Fellow at UNSW, Adjunct Professor at University of Sydney and a former Director of Public Prosecutions.

This opinion piece was first published in the Sydney Morning Herald.