bid on the Republican candidate and was prepared to die carrying it out

This is the moment a delusional man unloaded a Glock 17 pistol at a Las Vegas shooting range - 24 hours before he attempted to grab a police officer's gun in a bid to kill Donald Trump.

In CCTV footage - obtained exclusively by DailyMail.com - mentally ill Michael Sandford is seen plugging 20 rounds in to a target at the range during a $29 training session.

Sandford was arrested in a dramatic scenes the following day at a Trump rally in a Las Vegas casino on June 18 after going for the police officer's weapon as he asked for Trump's autograph.

He told police he had plotted to assassinate the Republican presidential candidate for a year and believed he would die during the bid.

Relaxing in to it: The gun range owner's told DailyMail.com that the 20-year-old became more competent during his session with the handgun

Aftermath: Las Vegas officers were pictured hustling Sandford away from the Treasure Island Casino in the city after he went for one officer's gun at a Trump rally

The footage has been released to DailyMail.com ahead of the next presidential debate in Las Vegas tonight.

Last month Sandford, a British citizen, pleaded guilty to federal charges and is awaiting sentencing as part of a plea deal.

He faces around two years in a US prison and will be deported after pleading guilty to be an illegal alien in possession of a firearm and disrupting an official function.

The 20-year-old could have faced up to 20 years in prison if he had been convicted at trial of the charges.

Court documents say Sandford acknowledged reaching for the gun while Trump was on stage during a campaign speech.

Fortunately did not get hold of the weapon before he was wrestled to the ground and arrested, and no shots were fired.

In security video footage obtained from Battlefield Vegas - a shooting range popular with tourists - Sandford is seen being schooled on how to shoot the 9mm Glock.

He was given a safety tuition before being taken by an instructor to a booth in the busy range.

Sandford is then seen shooting 20 rounds using the pistol.

Battlefield Vegas owner Ron Cheney told DailyMail.com that Sandford appeared 'nervous and apprehensive' when he first arrived and took hold of the weapon.

Cheney said: 'He rented a Glock 17, he said he wanted to learn how to fire a hand gun. Europeans for the most part have seen guns in the movies but have never held them in their hand.

'So the way he was, he was a little nervous and apprehensive, it was his first time shooting a gun.'

But Cheney said slightly built Sandford, who was seen wearing a gray t-shirt and large ear protectors, soon relaxed in to the 15-minute training session.

Autistic: Sandford was said by his family to have been diagnosed with autism. His lawyer told the court he was delusional at the time of his arrest

Prepared to die: Sandford told cops that he realized his plot might cost him his life. He left an easy trail for them, signing in to the range on the day before the rally

Tuition: The 20-year-old illegal was given expert advice by staff at the gun range on how to handle a handgun. The instructor saw 'nothing out of the ordinary', bosses told DailyMail.com

'By the time he was done with his magazine he was comfortable, he wasn't shaking anymore,' he said.

'The instructor said he was a nice kid and noticed nothing out of the ordinary.

'The staff explained to him how to hold a weapon, how to center it, how to aim a pistol.

'Usually from the movies people want to hold the gun sideways or with one hand, we show them how to properly hold a weapon, it's safer for everybody that way.

'He shot 20 rounds in total, it's usually a 17-round magazine but we put an extension on for him.'

Video footage shows Sandford leaving the range with the rolled up target in his hand.

A Glock 9mm handgun is one of the handguns officers in the Las Vegas Metropolitan Police are authorized to carry

Cheney also revealed the reason Sandford was unable to take the officer's weapon the next day - because he had a retention holster.

'My staff have retention holsters here for safety reasons, you can't just pull the gun out, there's either a lever that's flipped or a certain twist you put on the gun that allows it to expel from the holster.

Plea: Sandford's mother Lynne, of Dorking, Surrey, said her son was autistic and should be getting help, not jail

'And that's what the police officer had when he tried to go for the gun, it looks like it will come right out because you don't see any straps, but it won't release. That's why he couldn't pull it out.'

Cheney said his company was contacted by the FBI, Secret Service and the Las Vegas Metropolitan Police Department after the incident.

'They were here soon after it happened and they asked that we hold off from releasing any video or make any statements that may affect the case and we agreed,' he explained.

'It's a tough one, I feel bad for the kid, he has a mental illness, but if you want to kill someone you can't just get a slap on the wrist.'

Sandford's mother had told the judge in his case that he had been treated for obsessive compulsive disorder and anorexia as a youngster.

Lynne Sandford also said son had 'a lifetime of mental health problems' has autism and Asperger's syndrome and watches children's cartoons.

She said her son would not have understood the consequences of his actions and was on suicide watch while in a Nevada jail.

Family attorney Saimo Chahal added that Sandford was delusional at the time

According to court research Sandford did not have permission to be in the US and was unemployed.

He was originally from Dorking, in Surrey, and his mother told the BBC in July: 'He needs help not prison.'

Gun venue: Battlefield Vegas is one of the city's most popular destinations for tourists. There are no legal restrictions on people going to it and learning how to handle a weapon. In Sandford's home country, the United Kingdom, possession of a handgun is illegal

Papers filed at the court said he had been in the country for around 18 months and lived in Hoboken, New Jersey.

He had driven across the US to San Bernardino, California, and had been living out of his car before traveling on to Las Vegas.

The following day he went to the Treasure Island Casino where Trump was addressing a rally of 1,500 supporters amid tight security.

Attendees had to pass through metal detectors manned by Secret Service, police and casino security officials.

Asking to get an autograph from the billionaire, he tried to take a police officer's holstered gun before being tackled and frogmarched from the venue.

A Secret Service report said Sandford told officers he had been planning the assassination for around 12 months and believed he would die in the process.

He had also bought a ticket to a rally in Phoenix, Arizona, for later on Saturday as a back-up.

Sandford was carrying a UK driver's licence at the time he was arrested.