Within hours of a scissors-wielding man being shot dead by police at Central Station on Wednesday night, the force issued the type of statement we have come to associate with what it clinically refers to as "critical incidents". The statement said that the homicide squad would "now investigate all circumstances surrounding the incident".

"That investigation will be subject to independent review and all information will be provided to the Coroner," it said.

It's early days and the details of the shooting – which reportedly saw up to four shots fired – are yet to be fully understood.

The man - Danukul Mokmool - appeared highly distressed and possibly mentally ill, but again this is pure speculation based on grainy bystander video.

Extraordinarily, it has occurred almost exactly 20 years after one of Sydney's most tragic police shootings of a mentally ill person – that of Roni Levi on Bondi Beach on June 28, 1997.

Those two decades have seen much discussion about the need for better police training in handling mentally ill people and the introduction of Tasers as an alternative to bullets – areas in which there has been progress.

Yet one persistent call from sections of the legal community and some politicians remains unheeded: ending the practice of police investigating police.

As the police statement noted, the NSW police homicide squad will take the lead in investigating what happened at the florist shop tucked inside the Eddy Avenue entry to Central Station.

The "independent review" referred to is in fact conducted by another NSW police Local Area Command.

The only truly independent oversight of the police investigation will be from the newly created Law Enforcement Conduct Commission or LECC.

The LECC was created in response to recommendations of former shadow attorney-general Andrew Tink, who was give the task of examining the whole area of police oversight.

It replaces the Police Integrity Commission and functions of the NSW Ombudsman.

But as Fairfax Media reported when the bill was before Parliament, significant concerns have been raised about the adequacy of the new arrangements when it comes to ensuring police shootings are property investigated.

The acting NSW Ombudsman John McMillan warned the LECC model would offer diminished oversight of NSW police, including less power to monitor internal investigations into shootings and other "critical incidents".

Wednesday night's shooting is the first fatal police shooting since the Lindt Cafe siege that resulted in the death of gunman Man Haron Monis.

As such it is also the first test of the new oversight arrangements. LECC representatives attended the scene of the shooting at Central Station.

There has been no shortage of calls for the investigation of such incidents to be taken out of police hands altogether.

In 2013, then premier Barry O'Farrell commissioned former federal attorney-general Robert McClelland to conduct a review of how police shootings are investigated.

It followed the shooting by police of Adam Salter at his Lakemba home in November 2009 after police responded to information he was stabbing himself with a knife.

In its submission to the review NSW Legal Aid said it was concerned that the "premise" was that police should retain responsibility for investigating and reviewing critical incidents.

It concluded that past critical incident findings by the Ombudsman, the Police Integrity Commission and a deputy state coroner, Hugh Dillon, "raise questions of conflict of interest when NSW Police Force investigates the potential misconduct of a member of its own agency".

"For this reason, Legal Aid NSW is of the view that the review should explore the investigations of critical incidents by an independent body," its submission said.

The PIC also recommended a new, independent investigation body.

The Law Society of NSW said there was an "inherent conflict of interest" in police investigating police when civilians are killed or seriously injured as a result of police action.

But McClelland found no need to hand such investigations to an independent body – a finding slammed as a "whitewash" by Greens MP David Shoebridge.

The finding accorded with the long-held view of the NSW Police Association, which argues homicide detectives have the necessary skill to conduct proper investigations in a timely manner and that independent oversight is sufficient.

At this stage, there is no suggestion police acted improperly at Central Station. But what is certain that there will be enormous scrutiny of how the LECC performs in its first significant test.