Ben Roberts-Smith was taking his teenage daughters on a shopping day trip to Sydney when he was arrested getting off a Qantas flight and charged with war crimes.

The Victoria Cross recipient had flown from Queensland to NSW with his 15-year-old twins and partner Sarah Matulin on the morning of April 7 and all four were holding return tickets to Brisbane. 

Roberts-Smith, who will apply for bail today in Downing Centre Local Court, had treated his girls to an Easter school holidays expedition and none of the group had checked any luggage.

Federal authorities knew the 47-year-old was making the journey on Tuesday last week and could have arrested him when he returned to his home state that evening, a source close to Roberts-Smith said.

Roberts-Smith has been charged with five counts of 'war crime - murder' allegedly committed between 2009 and 2012 while he served with the Special Air Service in Afghanistan.

He believes authorities chose to arrest and prosecute him in NSW because his case would be more likely to succeed there than in 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 be tried by a jury.

Roberts-Smith's lawyers believe if their client faced a committal hearing in Queensland, where committals are still held, the evidence against him might be considered too weak for a trial to go ahead.

Australia's most decorated living soldier has been held for the past ten days at the Metropolitan Remand and Reception Centre at Silverwater in Sydney's west.

He was taken into custody after a five-year joint investigation by the Australian Federal Police (AFP) and the Office of the Special Investigator (OSI).

The Daily Mail previously revealed Roberts-Smith had repeatedly offered to present himself to police if they were going to charge him with war crimes.

He is accused under the Commonwealth Criminal Code of shooting dead an unarmed Afghan, murdering another with an SAS comrade, and ordering the execution of three more.

Roberts-Smith's arrest came almost three years after he lost a defamation action against Nine newspapers, which published a series of reports in 2018 accusing him of being a war criminal.

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

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

Two of the five Afghan men the former corporal is accused of murdering have never been identified by war crimes investigators.

Court documents show one of his alleged victims is described only as 'Person Under Control 1', or alternatively 'Enemy Killed in Action 3'.

Roberts-Smith is accused of murdering that Afghan male with another SAS member dubbed 'Person 68' at Syahchow in Uruzgan Province on October 20, 2012.

Another alleged victim who is only known to authorities as 'Person Under Control 2' or 'Enemy Killed in Action 4' was killed on the same day in the same place.

Roberts-Smith is accused in a court attendance notice of aiding, abetting, counselling or procuring an SAS rookie dubbed 'Person 66' to shoot dead 'Person Under Control 2'.

Three of Roberts-Smith's alleged victims are named in court documents, while two other former SAS members have been identified with pseudonyms as having killed detainees but are not charged with any offence.

Roberts-Smith is accused of aiding, abetting, counselling or procuring Person 4 to shoot dead Mohammed Essa on April 12, 2009 at Kakarak in Uruzgan Province.

He is also accused of intentionally causing the death of 'a person identified as Ahmadullah' at Kakarak on the same day.

Mohammed Essa was the father of Ahmadullah, whose prosthetic leg was taken as a trophy after he was killed, and later used as a drinking vessel at the SAS's Tarin Kowt base.

Roberts-Smith is further charged with aiding, abetting, counselling or procuring Person 11 to kill Ali Jan at Darwan in Uruzgan Province on September 11, 2012.

Ali Jan was the shepherd Nine newspapers claimed Roberts-Smith kicked off a cliff before ordering his execution.

Each of the alleged victims is described in the charge sheets as 'not taking an active part in hostilities' when they were killed.

AFP Commissioner Krissy Barrett held a press conference shortly after Roberts-Smith's arrest. 

'It will be alleged the victims were detained, unarmed and were under the control of ADF (Australian Defence Force) members when they were killed,' she said.

'It will be alleged the victims were shot by the accused, or shot by subordinate members of the ADF, in the presence of, and acting on the orders of, the accused.'

OSI director of investigations Ross Barnett said during the same press conference that prosecuting war crimes allegedly committed in Afghanistan was 'incredibly complex'.

Mr Barnett said the OSI had been investigating '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.'

The AFP and OSI have commenced 53 investigations involving allegations of war crimes committed by Australians soldiers in Afghanistan and 10 are ongoing.

One investigation resulted in former SAS member Oliver Schulz being charged with murdering a man called Dad Mohammad at Deh Jawz in Uruzgan Province on May 28, 2012.

Schulz was patrolling a wheat field when he allegedly encountered Dad Mohammad lying on his back with his hands and knees raised and shot him dead.  

The now 44-year-old was arrested on March 20, 2023 and spent a week behind bars before being granted $200,000 bail in Downing Centre Local Court.

Judge Jennifer Atkinson said any further time Schulz spent in custody would be 'onerous and difficult and dangerous' and it was likely his case would not go before a jury before 2025.

Schulz has been listed to face trial in February 2027.

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.

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.'

An OSI spokesperson added: '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. The CDPP did not acknowledge receipt of the questions.