We should've gone in earlier: commissioner

Jamie McKinnell and Dan McCulloch

Hindsight shows officers should have stormed Sydney's Lindt Cafe sooner to end the 2014 siege before two hostages died, NSW Police Commissioner Mick Fuller says .

Mr Fuller was one of the first commanders at the scene of the Martin Place attack in December 2014 which claimed the lives of hostages Tori Johnson and Katrina Dawson.

Responding to a coroner's report on the tragedy, Mr Fuller acknowledged the traditional "contain and negotiate" strategy which police adopted wasn't the best approach when it came to terrorists.

In the future, police would likely storm any such siege rather than wait, he suggested.

Coroner Michael Barnes on Wednesday found police waited too long during a 10-minute period after "maniac" gunman Man Haron Monis fired a shot at escaping hostages at 2.03am.

The gunman's ordering of the cafe manager, Mr Johnson, to his knees should have satisfied a "secondary trigger" for tactical officers to storm the stronghold, the coroner found.

But Mr Fuller, who was appointed police chief earlier this year, went further than the coroner when he told the Ten Network: "We probably should have gone in before the first shot."

"Early intervention for terrorist incidents is the way forward, knowing what we know now," he said.

"But nevertheless it's still a very dangerous tactic and people will potentially still lose their lives."

Ms Dawson was fatally hit by police bullet fragments when police entered the cafe at 2.14am.

Mr Fuller told reporters if a similar terrorist attack occurred now "we would respond with the same highly trained police but with a different philosophy".

"It hasn't just reshaped NSW Police - police in France and across Europe and other countries have learnt valuable lessons from Lindt Cafe in terms of contain and negotiate versus early intervention."

Mr Barnes found that while the containment strategy was appropriate in the early phase of the 17-hour ordeal, negotiators didn't adequately reassess the headway they had made with Monis.

His report suggested senior officers were unduly reluctant to initiate an assault in siege situations.

"When dealing with terrorists, this reluctance is problematic," the coroner said.

"(It) may not be the best response to a terrorist incident if the offenders believe that whether or not they survive, their cause will benefit from the publicity generated by a protracted siege."

Mr Fuller did, however, defend the contain and negotiate strategy in domestic-type situations.

"It has saved many lives and NSW Police is committed to it," he said.

The new commissioner said many of the 28 recommendations relating to policing were already being addressed.

A consultant psychiatrist brought in to assist police made unrealistic assessments of what was occurring and gave ambiguous advice, Mr Barnes found.

Mr Fuller said the force had already looked at bringing in different experts in future.

The report also found snipers had a 10-minute window during which they could have taken a "kill shot", but not only did they doubt a visible head belonged to the gunman, they also doubted their legal justification to use lethal force.

Mr Barnes called for greater protection for officers in terrorism incidents and Mr Fuller said the balance between taking a life and saving a life should never be taken lightly.