Unearthed yearbook quote linked to Luigi Mangione has people convinced it could provide clues to murder of UnitedHealthcare's CEO

Internet sleuths believe a yearbook quote, thought to have been pitched for the man charged with the murder of United Healthcare CEO Brian Thompson, could be linked to the fatal shooting.

Police announced the arrest of 26-year-old Luigi Mangione on Monday (December 10), after Thompson was shot dead last Wednesday (December 4) outside the Hilton hotel in Manhattan.

Mangione was taken into custody in Altoona, Pennsylvania, on gun charges, but was later charged by New York investigators with murder, possession of a loaded firearm, possession of a forged instrument and criminal possession of a weapon.

Luigi Mangione was arrested in Pennsylvania (Pennsylvania Department of Corrections)

In the wake of his arrest, internet sleuths began digging into Mangione's past and discovered a Reddit post believed to have come from the suspect.

Posted nine years ago from a since-deleted account, the post read: "So I'm in my last year of highschool, and I've been asked to give a quote that will be displayed with my picture in the school yearbook, for everyone to see.

"I've decided I'll use a quote from the great dunkster himself, and I'd like to hear some suggestions. Best one wins, good luck ya dunks"

Shared to the Reddit thread 'r/videogamedunkey', the post made reference to the YouTuber 'videogamedunkey', or simply 'dunkey', who known for his YouTube skits and essays that combine humor with criticism of video games.

It is unclear whether the post was definitely made by Mangione, but he did use a quote on his yearbook page that featured on the thread.

The post received a lot of responses from fellow fans of the YouTuber, but it was one in particular that caught people's attention in the wake of Thompson's death.

The post on Reddit has been attributed to Mangione (Reddit/r/videogamedunkey)

Apparently taken from one particular rant from the YouTuber, the quote read: "malphite you are a f**king worthless braindead scumf**k b**tard pile of trash mental d***face that should be gunned down in the street like the degenerate you are."

Since this kind of violent language is unlikely to have made it into a yearbook, it wasn't the one that Mangione used for his page.

However, taking into account how Thompson was shot dead in the street, one Reddit user posted a comment on the suggestion earlier today (December 10), which says: "This quote probably could have inspired something."

A picture of Mangione's year book shows that he ended up using a different quote from Dunkey; one which reads: "Anoda day, anoda play."

Mangione quoted the YouTuber in his yearbook (Reddit/u/hoochieandgucci)

This quote was among the suggestions on the original Reddit thread, with users seemingly left stunned now at the developments since it was first posted.

"Holy f**k," one Reddit user wrote after realizing Mangione's yearbook quote featured in the thread.

Another pointed out that links between the Reddit thread and the current events are tenuous, but notable.

They wrote: "My god… he was 18 8 years ago. This would be one wild coincidence, and with it being a deleted account…. Never be truly answered."

Mangione went to an all boys high school in Baltimore, where he achieved the title of valedictorian.