Two men have allegedly attempted to assassinate Donald Trump. One of them remains a mystery

Two men have now allegedly tried to assassinate former US president Donald Trump.

One, now sitting in a Florida detention centre, allegedly left behind handwritten multiple letters, Google searches, notebooks, and interviews.

The other, shot dead, left behind only a mystery.

A box that went unopened for months

Before he was allegedly spotted pointing the barrel of a rifle through the fence of Donald Trump's Florida golf course, a witness says 58-year-old Ryan Routh left a box at his home.

For months, the box went unopened.

As news broke of the apparent assassination attempt and Routh's name and photo began circulating, the unnamed civilian finally opened it.

Inside, according to legal documents, was "ammunition, metal pipe, miscellaneous building tools, four phones, and various letters".

One letter is addressed simply to "The World".

"This was an assassination attempt on Donald Trump but I am so sorry I failed you," it reads.

"I tried my best and gave it all the gumption I could muster."

The letter goes on to offer $US150,000 ($NZD240,000) to "whomever can complete the job".

Inside the Nissan Xterra Routh allegedly used as a getaway vehicle, police say they found another six phones, 12 pairs of gloves, extra licence plates, and more handwritten notes.

A list of dates and venues allegedly noted appearances by the former president.

A notebook allegedly contained dozens of pages "filled with names and phone numbers pertaining to Ukraine, discussions about how to join combat on behalf of Ukraine, and notes criticising the governments of China and Russia".

In a February 2023 book, officials say Routh stated he "must take part of the blame" for Trump being "brainless".

"But I am man enough to say that I misjudged and made a terrible mistake and Iran I apologise," Routh allegedly wrote in the book, titled Ukraine's Unwinnable War.

According to The New York Times, the book at times referred to Trump as a "fool", an "idiot", and a "buffoon", and compared him to Russian President Vladimir Putin and former Brazilian president Jair Bolsonaro.

In the lead-up to the incident, officials say Routh travelled from Greensborough North Carolina to West Palm Beach, Florida, a distance of at least 1200 kilometres.

Once in Florida, they say his phone pinged off cell towers near Trump's golf course and the former president's Mar-a-Lago residence multiple times between 18 August and 15 September.

At 1.59am on 15 September, according to an initial legal document, Routh's phone allegedly placed him at the tree line of the golf course.

Twelve hours later, a Secret Service agent would spot the rifle barrel poking through the fence and open fire.

In less than two weeks, federal prosecutors have already presented a mountain of documentation.

It puts this case in stark contrast to the July assassination attempt.

On the other side of the country, another would-be assassin

Thomas Matthew Crooks was just 20-years-old when he was shot dead by a Secret Service sniper.

Moments before his death, he had opened fire at a crowded campaign rally in Butler, Pennsylvania, injuring the former president.

One man was killed and two others were critically injured in the attack, all three of them civilians attending the rally.

Authorities say Crooks left behind no apparent manifesto, no links to other groups or allies, and no motive they have uncovered so far.

Crooks, an engineering sciences graduate, worked as a dietary aide at a Pittsburgh nursing home.

His parents were both licensed professional counsellors, with his mother listed as a Democrat on voting records.

Crooks would have been eligible to vote for the first time in the 2024 election.

A registered Republican, he had also previously donated to a progressive cause, and his father and older sister were Libertarians.

FBI officials say he had received multiple packages, some labelled "hazardous material", in the months leading up to the attack.

On a phone later discovered at his Bethel Park home, authorities say they found online searches for several political figures and locations.

He had also searched "major depressive disorder".

FBI deputy director Paul Abbate told a Senate committee hearing the FBI had discovered two social media accounts they believed to belong to Crooks.

Comments made by one account in 2019 and 2020, Abbate said, appeared to "reflect anti-Semitic and anti-immigration themes" and "espouse political violence".

But, according to Abbate, the second account shared "differing points of view".

On 6 July, he registered to attend the rally. And on the same day he used his laptop to Google, "how far away was Oswald from Kennedy?"

The search was a reference to the 1963 assassination of then-US president John F Kennedy by Lee Harvey Oswald.

Sometime in the week before the attack, Crooks approached his boss with a request - he wanted to take the upcoming Saturday off.

He had to do something important, he told them.

On the Friday before the shooting, he spent much of his time at a gun range, before visiting a hardware shop and a gun shop the next morning.

Then he climbed into his car and drove to the Butler rally.

At 3.50pm, the FBI says Crooks flew a drone over the site for 11 minutes.

Authorities say they later found the drone inside his car, along with two explosive devices. Another explosive device and more than a dozen firearms were also found at his home.

At exactly 33 seconds past 6.11pm, he would open fire.

Investigations continuing into both alleged assassination attempts

Days after the Florida attack, the Secret Service released its internal review into Thomas Matthew Crooks's attack.

The incident is being investigated by multiple organisations, including the US Department of Justice, the Secret Service, and the FBI.

It has been classed as an act of domestic terrorism.

Two days after the Pennsylvania shooting, the FBI had already conducted 100 interviews, searched Crooks's home and car, and received hundreds of tips.

The special agent in charge of the FBI's Pittsburgh field office, Kevin P Rojek, said their analysis of Crooks' search history had still revealed no "definitive ideology".

"It's really been a mixture," he told The New York Times, labelling the Trump rally a "target of opportunity".

Ryan Wesley Routh has been charged with possession of a firearm by a convicted felon and possession of a firearm with an obliterated serial number.

Prosecutors say they plan to charge him with the attempted assassination of Donald Trump.

Public defenders assigned to represent him told a court the letters allegedly written by Routh showed he intended to fail in his attempt.

His legal team argued the apparent assassination was "perhaps … an attempt at publicity", intended to "make a few more people stop and think about how wonderful our democracy is".

Such a charge would carry a maximum penalty of life in prison.

The investigation is ongoing, and a judge has ruled Routh will remain behind bars for the time being.

- ABC