Ben Roberts-Smith believes authorities chose to arrest and prosecute him in NSW because his war crimes case would be more likely to succeed there than in his home state of Queensland.

NSW no longer runs committal hearings at which the prosecution brief is weighed by a judge to determine whether there is sufficient evidence to send a person to trial, whereas Queensland still does.

Roberts-Smith's lawyers think if the Victoria Cross recipient faced a committal hearing in Queensland, the evidence against him might be considered too weak for a trial to go ahead.

The 47-year-old father-of-two was arrested on April 7 as he arrived on a Qantas flight at Sydney Airport from Brisbane and charged with five counts of 'war crime - murder'.

He was taken into custody in front of his twin 15-year-old daughters and partner Sarah Matulin, then filmed being led from the aircraft to a waiting police vehicle.

Roberts-Smith is accused of shooting dead, or ordering subordinate soldiers to execute, five unarmed detainees while serving with the Special Air Service in Afghanistan between 2009 and 2012.

A source close to Roberts-Smith said arresting Australia's most decorated soldier in NSW was a deliberate ploy by federal authorities to give prosecutors a 'forum advantage'.

'The pathway to trial in NSW is markedly more favourable to the prosecution,' the source said. 

'Committal hearings have largely been abolished, replaced by fast-tracked case conferencing and early disclosure. 

'By contrast, Queensland retains a committal process that allows the defence to test the prosecution case - including cross-examining witnesses - meaning weak cases can be exposed and, in some instances, discontinued before trial.'

Roberts-Smith has lived in Queensland since he left the SAS in 2012 and none of the key prosecution witnesses is based in NSW. 

Each of the charges against Roberts-Smith carries a maximum penalty of life in prison. He has always denied involvement in any unlawful killings.

The case against Roberts-Smith will be run by the Commonwealth Director of Public Prosecutions (CDPP) and his defence funded by Afghanistan Inquiry Legal Assistance Scheme (AILAS).

CDPP policy sets out exactly how the appropriate jurisdiction in which to prosecute a criminal matter should be determined.

The policy states no consideration can be given to 'any real or perceived forensic advantages of the procedure, the laws of evidence or the disclosure regime of a particular jurisdiction'. 

Roberts-Smith was charged after a five-year joint investigation by the Australian Federal Police (AFP) and the Office of the Special Investigator (OSI).

OSI director of investigations Ross Barnett has said that prosecuting war crimes allegedly committed by Australian Defence Force (ADF) personnel in Afghanistan was 'incredibly complex'.

Mr Barnett said the OSI had examined 'literally dozens of murders alleged to have been committed in the middle of a warzone, in a country 9,000km from Australia that we can no longer access'.

'So, the challenge for investigators is - because we can't go to that country - we don't have access to the crime scene...' he said.

'So we don't have photographs, site plans, measurements, the recovery of projectiles, blood-spatter analysis, all of those things we'd normally get at a crime scene.

'We don't have access to the deceased - there's no post-mortem, therefore there's no official cause of death, there's no recovery of projectiles to link to weapons that might have been carried by members of the ADF.'

Instead, the case against Roberts-Smith will rely on testimony given by former SAS members, with Nine newspapers reporting that about two dozen would be subpoenaed to give evidence.

Four of Roberts-Smith's onetime comrades - known as Person 4, Person 11, Person 66 and Person 68 - have been implicated in the five alleged murders.

Two of the five Afghan men Roberts-Smith is accused of murdering have never been formally identified by war crimes investigators.

AFP Commissioner Krissy Barrett would not discuss why Roberts-Smith had been arrested at Sydney Airport when she spoke at a press conference on April 7.

'There's a number of operational considerations that we factor into our planning and when to effect an arrest and how,' she said. 'But I'm not going to go into that detail.' 

Nine newspapers reporter Nick McKenzie and freelance journalist Chris Masters first accused Roberts-Smith of war crimes in a series of reports published in 2018 and subsequently won a defamation case against him.

McKenzie has put forward a theory about why authorities chose to apprehend Roberts-Smith in NSW, rather than Queensland or Western Australia, where he previously lived.

'One well-placed source suggested investigators might have waited to arrest Roberts-Smith in NSW because they wanted access to a wider and more diverse jury pool,' McKenzie wrote on April 10.

'Roberts-Smith, who clearly knew this was coming, might have preferred a jury in a more conservative state, either his original home of Western Australia or his adopted hometown of Brisbane.'

The source close to Roberts-Smith rejected that proposition. 

'Suggestions by Nick McKenzie over the weekend that this was about accessing a broader jury pool miss the point,' the source said.

'The more immediate forensic reality is that this is a case dependent on witness evidence alone. 

'In the Office of the Special Investigator's own words, this is not a case built on objective or forensic evidence.' 

The source said the CDPP would consider NSW a more favourable jurisdiction.

'There is no access to crime scenes, no projectile recovery, no blood-spatter analysis, and no post-mortem material,' the source said.

'Against that backdrop, legitimate questions arise as to why the arrest occurred in a jurisdiction with a more prosecution-friendly pre-trial process.

'In that context, the choice of jurisdiction, and the manner of arrest, warrants scrutiny, including against the requirements of the CDPP prosecutions policy as to the appropriate forum.' 

The Daily Mail previously revealed Roberts-Smith's legal team had repeatedly told the AFP and OSI he would present himself 'at a time and place of their choosing should any charges be brought'.

The federal government has reportedly allocated $318million over the past decade to investigate war crimes allegedly committed by Australian soldiers in Afghanistan.

Former NSW Supreme Court judge Paul Brereton conducted a four-year inquiry for the Inspector-General of the Australian Defence Force, and in November 2020 published a damning report.

Justice Brereton found 'credible information' 25 Australian special forces personnel had been responsible for 39 unlawful killings in Afghanistan, along with cover-ups and other misconduct.

Since then, the AFP and the OSI have commenced 53 investigations, 10 of which are ongoing.

One investigation resulted in former SAS member Oliver Schulz being charged with murdering an Afghan man at Deh Jawz in Uruzgan Province in May 2012.

The source close to Roberts-Smith noted Justice Brereton was a NSW Supreme Court judge before, during and after he conducted his Afghanistan inquiry.

He sat on the Supreme Court bench for 18 years until his retirement in May 2023.

'While judges are independent, they are also human beings,' the source said. 

'The optics of Ben being tried for war crimes by a colleague of Paul Brereton leaves a lot to be desired. Justice needs to be seen to be done - it is not enough to just say it will be done.'

Daily Mail asked the AFP, OSI, CDPP and Attorney-General's Department who had elected to have Roberts-Smith charged in NSW and whether that state was chosen to give the prosecution an advantage.

The CDPP did not respond to those questions, and no agency answered an inquiry about whether trying Roberts-Smith before a NSW Supreme Court judge might raise concerns about perceived bias or impartiality.

An AFP spokesperson said: 'This was a joint investigation by OSI and the AFP. Investigators made the arrest at the most appropriate time and location for operational needs. No further comment will be made.' 

About an hour later, an OSI spokesperson stated: 'I understand you’ve also received a response from AFP Media on this - just confirming that the OSI has nothing further to add to their response.' 

A spokesperson for the Attorney-General's Department directed inquiries to the OSI. 

Roberts-Smith, who as well as holding the Victoria Cross earned a Medal for Gallantry in Afghanistan, will apply for bail at Downing Centre Local Court on Friday.