What makes an assassin? Psychologists take you inside their warped minds - and why Trump's shooting was 'probably NOT political'

When there's a mass shooting, the killer often leaves a trail of clues. These days, it's usually a sinister manifesto, cries for help on social media or incriminating search history. 

But Americans have been left with sea of questions and few answers in the wake of an assassination attempt on former President Donald Trump's life.

The shooter, Thomas Matthew Crooks, 20, has virtually zero online footprint. He has no known TikTok, Instagram or Snapchat. No has no friends who've come forward. 

And like other US assassins in history, his politics are ambiguous. He was a registered Republican and described by a classmate as 'definitely conservative'. Yet Mr Crooks also donated a small sum to a progressive movement in 2021. 

Dr Rachel Toles, a licensed clinical psychologist based in California, who specializes in the study of violent criminals told DailyMail.com that politics may have had little to do with the shooting - as astonishing as that may seem.

Thomas Matthew Crooks attempted to kill former President Trump at a campaign rally using a semi-automatic AR-15 rifle. He was shot dead at the scene by Secret Service

From her experience, Dr Toles said that people in these scenarios often suffer from an extremely damaged ego, and have a desire to take out someone who has what they most covet - which could be success, popularity or good looks. 

It's possible that former President Trump could've represented something Mr Crooks deeply desired - fame, success or respect.

'Trump gets more attention than anyone on the planet. 

'And now we're talking about an invisible kid who no one talked to in school unless they were kind of picking on him,' Dr Toles said.

She added: 'So we're talking about somebody who feels incredibly invisible, and he's targeting the most visible man on the planet. 

'So I do think it's more about that, than it is about political Donald Trump.'

Dr Nicholas Kardaras, who has psychoanalyzed a number of high-profile teenage killers over the years, agreed that it could be 'Trump represents the alpha male that he [the shooter] couldn't be in school.'

But he is not convinced there was no political influence at play here.

Dr Kardaras said Crooks may have been radicalized by the extreme sides of either the conservative or liberal movements.

The killer's donation to Democrats in 2021 may imply he was turned off Trump and viewed him as a threat to democracy after the January 6 riot at the Capitol. 

Or perhaps he felt Trump was not conservative enough during his presidency, which has been a criticism from the far right this campaign due to Trump's softening on abortion, for example.

Psychologists spoke to DailyMail.com about a number of common drivers of violent criminals, saying that assassins have more in common, generally with mass murderers than serial killers

Both Dr Kardaras and Dr Toles believe these killers share more in common with mass shooters than serial killers or people who kill someone in their personal life. 

Serial killers tend to be motivated by an internal drive to dominate and hunt other humans - and tend to have high self esteem, Dr Toles said.

By contrast - people who try to shoot political figures or take a gun to a school usually are doing so in order to get attention.

At this point, authorities are unsure what Mr Crooks personal beliefs were.

So experts can only make predictions based on what science has discovered thus far.

There's a long history of experts from the FBI and academia studying the minds of violent assassins, mass shooters and serial killers. 

Dr Kardaras said the political assassin normally falls into two categories - those driven by the idea that their actions will make large political or social change and those who are driven by the idea that murdering someone will make them 'immortal'. 

Both are likely to have some sort of mental health issue - be it delusions, depression or paranoia. 

Take John Wilkes Booth, for example, the man who murdered former President Abraham Lincoln in 1865. 

Mr Booth did so under the impression that killing President Lincoln would lead to a revitalization of the South after the Civil War, Dr Kardaras said. 

He convinced himself that his actions could change the course of history. 

Former assassination attempts on sitting Presidents have been carried out  by killers motivated by politics and insanity or infamy, which are Dr Kardaras two theories

But assassins are much more likely to be driven by attention, infamy and a general delusion that murder will make them 'somebody' than by politics, like Mr Booth was. 

Take assassins like John Hinckley Jr - who attempted to shoot former President Ronald Regan, believing that doing so would impress the actress Jodie Foster, whom he had become fixated on after seeing her perform in the movie Taxi Driver. 

Mr Hinckley called his attempt on President Regan's life, 'the greatest love offering in the history of the world.' 

Other examples of this type of assassin are Mark Chapman, who murdered John Lennon in order to bring attention to the Book The Catcher in the Rye and rid of the world of the 'biggest phony of them all'.

They are convinced that their actions will fulfill whatever their delusional desires are - or will fulfill their deep desire for attention. 

It could be that Mr Crooks was in this camp, hungry for attention, Dr Toles said. 

According the Secret Service Exception Case Study Project, which is one of the most extensive study of assassins or attempted assassins, many more assassins are driven by delusions and fame than by a desire to change the political landscape. 

Study author and psychologist Robert Fein, who interviewed 83 people who attempted assassinations, told NPR, 'it was very, very rare for the primary motive to be political, though there were a number of attackers who appeared to clothe their motives with some political rhetoric.'

The shooter had an interest in firearms and was bullied at school, former classmates shared

More commonly, Dr Fein said, these people, 'experienced failure after failure after failure, and decided that rather than being a "nobody," they wanted to be a "somebody"'.

In Dr Kardaras' eyes, it's likely that Mr Crooks was motivated by a combination of these factors. 

He said it appears the gunman could've had an inferior, 'I'll show you' mindset, but 'the fact that he targeted a political figure shows me that there was also some, I would infer that there was also some political agenda there.' 

Another factor that could've contributed to his attempt on former President Trump's life is the fact that Mr Crooks had an interest in firearms, going back at least as far as high school. 

He tried out for his high school rifle team, but did not earn a place on the team. 

He also had a membership to a local firing range, The Clairton Sportsmen's Club, the BBC reported. 

Dr Kardaras said that an early interest in guns and violent video games is incredibly common in school shooters.

'Not every kid who plays violent video games becomes a school shooter, but every school shooter has been been heavily immersed in violent first person shooter games and then also secondarily had access to guns' he said. 

It's unclear if Mr Crooks played video games - but if he did, it's possible that this could've increased his aggression and blurred the line between reality and fiction, he said.

He explained that constantly being immersed in violent graphics could influence your aggression and how you respond to the world around you. 

He added: 'if you run the wolves, you're going to become a wolf.'