He also did not initially reveal that he backed up his car towards Michael Brown and his friend,

Darren Wilson changed his story following the immediate aftermath of the fatal shooting of unarmed black teen Michael Brown to include events about which he initially denied all knowledge.

Evidence presented to the grand jury and reviewed by MailOnline has revealed a crucial difference between the officer's first account of events given to his squad supervisor on the scene and his second statement to St Louis County detectives investigating the shooting.

In Wilson's now very public account of his encounter with Michael Brown and Dorian Johnson on August 9 he has claimed that he asked Brown and Wilson to move to the sidewalk rather than walk in the street.

When they walked on, Wilson has repeatedly stated, he realized they matched the description of two suspects wanted in connection with the robbery of nearby Ferguson Market. A youth matching Brown's description had stolen a box of Swishers cigarillos.

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It was this realization, he stated, that caused him to reverse his vehicle and sparked the car-side confrontation that left Brown dead on the street with six bullets in his body.

But the sworn testimony of Wilson's squad supervisor directly contradicts this account.

Wilson's supervisor was the first officer to speak with the 28-year-old cop following the shooting. The men spoke before St Louis County Police had even been notified of the incident and before the medical examiner or investigating officers had arrived on the scene.

At that time, the supervisor said:'He [Wilson] did not know anything about the stealing call.'

When pressed by the attorney questioning him, the officer reiterated that Wilson, 'did not know anything'.

Asked, 'He told you he didn't know about there being a stealing at Ferguson Market?'

The officer responded, 'Correct.'

Nor did he make any mention of reversing his police car back towards the youths.

In fact the squad supervisor stated that, in several subsequent conversations, Wilson said 'he did not have that call.'

Yet two hours after speaking to his supervisor, 28-year-old Wilson gave a very different account to the St Louis County Police detective assigned to conduct a cursory interview with the cop.

In his testimony the St Louis detective, whose name has been redacted in the transcripts that are among the thousands of pages of grand jury evidence made publicly available by Prosecutor Bob McCulloch, recalled: 'He tells me he was leaving an unrelated sick case call and was driving, it would be west on Canfield Road.

'As he's driving he hears a call that was not assigned to him for a stealing in progress at 9101 West Florissant Avenue and he provides us with that address and the nature of the call was a stealing.

'He said that the call comments indicated the suspect description was a black male wearing a black shirt and brown shorts, and that an additional call comment indicated that taken during the stealing were Cigarillos.'

It is a marked discrepancy from Wilson's admission minutes after the shooting that he had no knowledge of that incident. In the time between that denial and this detailed recollection of the suspect's description and goods stolen, Wilson had driven himself back to Ferguson Police Department Headquarters on the city's Main Street.

He had washed his hands clean of any blood and he had been permitted to bag up his own gun as evidence - acts entirely contrary to St Louis County procedure.

And in the course of an hour, he had spent time in the company of the Lieutenant Colonel, his Chief of Police Thomas Jackson, as well as an attorney from the Fraternity of Police Officers.

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Wilson was sitting with all three when the St Louis County detective arrived to interview him.

Before he could, Wilson's Lieutenant Colonel made the decision to take the officer to hospital for treatment.

Medical records show that what Wilson described as a struggle for his life left scant physical injury.

Wilson was diagnosed with bruising and given medication described by his treating physician as 'essentially prescription strength Aleve.'

It is now also known that the decision to X-ray Wilson was not a clinical one made by his medic but in response to the Chief of Police's direct request.

HOW HIS STORY CHANGED What he told his squad supervisor 'He [Wilson] did not know anything about the stealing call.' What he told St Louis detective 'As he's driving he hears a call that was not assigned to him for a stealing in progress at 9101 West Florissant Avenue and he provides us with that address and the nature of the call was a stealing.' What he told the FBI 'He heard over the radio a call for a stealing in progress…He heard it was at a market, he didn't hear which one and he heard a description over the radio saying the subjects were walking towards the QuikTrip, stole Cigarillos and one subject was wearing a black shirt' What he told grand jury 'When I start looking at Brown, first thing I notice is his right hand, his right hand is full of Cigarillos. And that's when it clicker for me because I now saw the Cigarillos, I looked in my mirror, I did a double check that Johnson was wearing a black shirt, these are the two from the stealing.' Advertisement

It was Chief Thomas who released CCTV footage of the Ferguson Market robbery showing Brown swiping the cigarillos and squaring up to a clearly intimidated store keeper. His actions drew harsh criticism from those who saw it as an attempt to smear Brown and shift focus from Wilson.

Chief Thomas's claim that he released the tapes in response to media requests was subsequently shown to be untrue.

In his interview with the St Louis County detective Wilson recalled Brown handing something to Dorian Johnson and saying something like, 'Here take these.' But he said he could not see what was handed.

By the time officer Wilson gave his account to the FBI agent assigned to interview him on 28 August his power of recall had grown ever more impressive.

The Federal agent told the Grand Jury that Wilson stated, 'He heard over the radio a call for a stealing in progress…He heard it was at a market, he didn't hear which one and he heard a description over the radio saying the subjects were walking towards the QuikTrip, stole Cigarillos and one subject was wearing a black shirt.

'Officer Wilson's attention was then drawn to Michael Brown and he noticed that Michael Brown's hands were full of Cigarillos. He looks in his rear view mirror and also saw that Dorian was wearing a black T-shirt.'

Crucially, the FBI agent continued, 'Thinking back on the call, Michael Brown was wearing a gray t-shirt and the call was they stole Cigarillos and one was wearing a black shirt.

'So kind of putting tow and two together or thinking that these might be the two guys, he puts the car in to reverse.'

Wilson got out of the car to give chase following the struggle for his gun that saw the first shot fired, because, the agent stated, 'Michael Brown was a fleeing felon. And he was just doing his job, those were his words.'

None of the interviews - not the first account given to his Squad Supervisor, or the cursory interview conducted within hours of the shooting by the St Louis detective or the FBI's own interrogation - were recorded.

Asked why he had not recorded nor noted down Wilson's vital first account, his squad supervisor said, 'Number one, I did not have a recorder. Number two, I didn't take notes because at that point in time I had multiple things going through my mind besides what Darren was telling me.'