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A.K.A.: "Dexter" Copycat Killer
Classification: Murderer
Characteristics: Dismemberment - Compared himself to the fictional serial killer "Dexter Morgan"
Number of victims: 1
Date of murder: October 10, 2008
Date of arrest: October 31, 2008
Date of birth: July 4, 1979
Victim profile: John Brian "Johnny" Altinger, 38
Method of murder: Stabbing with knife
Location: Edmonton, Alberta, Canada
Status: Sentenced to life in prison with no chance of parole for 25 years on April 12, 2011

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Mark Andrew Twitchell (born July 4, 1979, Edmonton, Alberta), is a Canadian who was convicted of first degree murder in the death of John Brian "Johnny" Altinger.

His trial attracted substantial media attention due to the fact that Twitchell was inspired by the character Dexter Morgan, of the Dexter television series, a forensic bloodstain pattern analyst for the fictional Miami Metro Police Department who moonlights as a serial killer.


Twitchell was an aspiring filmmaker in the fall of 2008. In September 2008 he shot a short horror film at a garage he rented in the south end of Edmonton.


John Brian "Johnny" Altinger was a 38 year old male who worked at an oilfield equipment manufacturer at the time of his disappearance. He informed his friends that he was meeting a woman he had met on the online dating website His friends became concerned when they received strange emails from Altinger, explaining that he had met a woman who was taking him on a long vacation to Costa Rica. Altinger's boss received a resignation letter by email, but never got a response to his request for a forwarding address for Altinger's final paycheck.

After growing more and more suspicious, several of Altinger's friends broke into his condo only to find his passport, dirty dishes and no indication anything had been packed. A homicide investigation was soon launched by the Edmonton Police Service.


The key piece of evidence presented by the Crown at Twitchell's first degree murder trial was a document, entitled "SKConfessions" where the SK stood for Serial Killer, which was recovered from Twitchell's laptop despite being deleted. The document begins with the passage:

"This story is based on true events. The names and events were altered slightly to protect the guilty. This is the story of my progression into becoming a serial killer."

It goes on to describe in detail the author's extensive planning, failed first attempt, and successful second attempt at murdering a man by luring him to his garage using fake online dating profiles. It also describes the process of dismembering the victim's body and his numerous attempts to dispose of the remains. During his trial, Twitchell admitted to killing Altinger and authoring the document. However, he contended that he acted in self defense and that much of the document was a fictionalization of the events. He claimed that the mindset of the author, which portrayed the killing as deliberate and intentional, was sensationalized in an attempt to make a more compelling novel.

Attempted murder

Twitchell, convicted of first degree murder in the online luring death of Johnny Altinger, still faced an attempted murder charge for his alleged attack on Gilles Tetreault. Tetreault testified that he was lured off the website expecting a date with a woman, only to be attacked by a man in a mask with a stun baton when he arrived at a garage rented by Twitchell. Crown prosecutors had not immediately decided if they would pursue the charge of attempted murder upon securing a conviction of first degree murder. But a conviction of attempted murder would not add to the life sentence Twitchell had already received.

On June 17, 2011, an attempted murder charge against convicted killer Mark Twitchell was stayed in the Court of Queen’s Bench of Alberta. Crown prosecutors have one year to resurrect the charge, which was laid for an alleged attack by Twitchell on Edmontonian Gilles Tetreault almost three years ago.

Media Controversy

Extensive media coverage of the case created debate both inside and outside of the courtroom with observers arguing in favour and against the media reporting on "sensational" details of the crime.

Prior to the criminal trial taking place, Crown prosecutors and the defence also sought vast publication bans and sealing orders over the police evidence, preventing the media from reporting on the details of the case until the jury would hear it during the future trial. The media fought the application, but the judge eventually agreed to both a sealing order and publication ban, stating in his ruling that "there is a real risk that pre-trial publicity will undermine the accused's constitutionally protected right to a fair trial."

The jury pool was then polled through a "challenge for cause" procedure to determine if a potential juror had been influenced by extensive media coverage prior to the publication bans taking effect. When the bans were lifted, a substantial media presence attended and reported on the trial, including American television programs Dateline NBC and CBS 48 Hours Mystery. A forthcoming true crime book is also in the works by journalist and author Steve Lillebuen.

After his first degree murder conviction, Twitchell used the extensive media coverage of his case as grounds for an appeal. He argued in his notice of appeal that "the media attention surrounding my case was so extensive, so blatant and so overtly sensationalized that it is unreasonable to expect any unsequestered jury to have remained uninfluenced by it, regardless of judges instructions in the charge."The result of his appeal has not yet been decided.


Killer filmmaker appeals sentence, blames media

By Toni Blais - Edmonton Sun

May 10, 2011

EDMONTON - Wannabe filmmaker Mark Twitchell plans to appeal his first degree-murder conviction in the dismemberment-slaying of John Altinger at a south Edmonton garage.

Twitchell - who is serving a life sentence with no chance of parole for 25 years at a Saskatchewan prison - sent a hand-written notice of appeal that was filed Monday. In it, he blames the media for the jury's guilty verdict.

"The media attention surrounding my case was so extensive, so blatant and so overtly sensationalized that it is unreasonable to expect any unsequestered jury to have remained uninfluenced by it, regardless of (the) judge's instructions in the charge," writes Twitchell, 31.

Twitchell also says "sufficient evidence was presented to raise reasonable doubt on all required bases," but suggests his defence lawyer did not properly "address key points on state of mind and credibility."

He says those key points include his "advanced knowledge" of computers and "significant differences" between himself and a document found buried in the deleted files of his laptop called SKconfessions, which the Crown called his diary and he claimed was a work of fiction.

Twitchell claims his computer knowledge is "much more advanced" than the average user which undermines the implication he would use one to "carry out a crime" and "destroys" the suggestion he deleted SKconfessions to "hide or erase evidence" or thought it "unrecoverable."

He also claimed the "significant differences in the philosophical world view and individual search for meaning" between himself and SKconfessions was not discussed.

Twitchell also goes after Crown prosecutors for improperly using evidence, including his lying to his girlfriend, his wife and police, to take away his credibility.

"This led the jury to make an inappropriate and skewed character judgement, concluding I'm a lifetime liar," he said, claiming the evidence was only supposed to be used to determine the veracity of SKconfessions.

"The Crown's theory leans on too many fallacies of logic and contradictions in reasoning to make any sense," he concludes. "This must be corrected."

Twitchell was handed a life sentence on April 12 after a jury convicted him of the Oct. 10, 2008, killing of Altinger.

The Crown alleged Twitchell used an Internet dating service to lure Altinger, 38, to a rented garage on the pretext of a date or possible sexual encounter.

Once there, he hit him on the head with a pipe and used a hunting knife to stab him to death before dismembering his body and disposing of his remains down a city sewer.

During the three-week trial - which garnered international attention - the jury heard Twitchell, a married father, was an aspiring filmmaker who had a fascination with Star Wars, weapons and TV serial killer Dexter Morgan.

Court heard Twitchell juggled the life of being a young dad with having a girlfriend on the side and a female American online pal with whom he shared dark secrets.


Convicted killer Mark Twitchell played with victim's skull, says court document

By Dean Bennett - The Canadian Press

April 12, 2011

Some of the description in convicted murderer Mark Twitchell's alleged diary was so lurid that the Crown, defence and judge decided it was too inflammatory to be presented to the jury.

Twitchell, 31, was convicted of first-degree murder Tuesday for killing a stranger, Johnny Altinger, at a southside garage on Oct. 10, 2008.

The evidence the jury didn't hear was at times as disturbing as the facts they did hear.

WARNING: Graphic content may disturb some readers.

Twitchell, if one passage on the document found on his laptop is true, cut the head off his victim and played with it like a hand puppet.

"I grabbed his jaw with my gloved hand and moved it while making a funny voice to make it look like it was talking, and chuckled to myself at the total silliness of it all," it read.

The passage was among many that were under a publication ban until the jury was sequestered Tuesday afternoon to reach a verdict.

Although the names and places were fictionalized, the Crown suggested the document described real events in Twitchell's life surrounding the death of Altinger.

Twitchell admitted authoring the document, which was written in the first person and titled "SKConfessions."

Twitchell said SK stood for his writing hero Stephen King but said it also meant "serial killer."

The opening line was, "This is the story of my progression into becoming a serial killer."

However, he insisted it was a work of fiction based loosely on the events of his life.

He admitted he lured Altinger, and another stranger a week earlier, to the garage — but said it was not to harm them.

He did it as a prank, he said, to encourage them to help hype a slasher-movie project of his.

The first man, Gilles Tetreault, managed to fight back and flee the garage, just as described in the document.

But Twitchell testified that Altinger got angry when he learned of the prank and attacked him. In self defence, Twitchell said, he knifed him in the heart, then panicked and cut up the body and dumped it down a sewer.

The "SKConfessions" document described the death of the Altinger character, named Jim, as a cold-blooded attack with a pipe, followed by graphic details of the dismemberment, including the line about working the jaw of the skull.

Twitchell was not asked by either Crown or defence to affirm or refute specific aspects of the actual dismemberment, but did not take issue in court with what was written about the dismemberment in the document.

That information and similar notes were not presented to the jury because the judge agreed with Crown prosecutors and the defence that the inflammatory nature of the material outweighed its value as evidence.

Among the other information not shown to the jury were the author's thoughts on organized religion and on murdering human beings.

Religion, he wrote, is for suckers.

"There are no deities or religious undertones in my life at all," he wrote.

"I have no place for them and I find the whole concept of religion detestable. It's all a big, corrupt power grab designed to take advantage of simple-minded common folk."

He talked about cutting open the torso of the victim and watching the organs slowly collapse. "If I had a sense of smell this might be disgusting for me. But I only find it fascinating."

The author talked about killing. "Most people fantasize and it only ever stays a fantasy. They don't have the disposition or the stomach to go all the way with their dark urges. But I do."

Later he went on: "I do not have any reservations about disposing of the negative people in this world who deserve a one-way ticket to the afterlife, if such a thing exits."

He said one person he really wanted to dispatch was an ex-boss.

The man, he wrote, was "a twisted old fart who hated life and everything in it. I owed it to the world to remove him from its glorious surface and would take my chance when I was ready."

The author also self-diagnosed himself as mentally unstable, but Justice Terry Clackson ruled the jury should not hear it because the terminology was emotionally loaded and that Twitchell, if he was writing it as the truth, would not be in a position to properly diagnose himself.

"I had found out through introspection and discussions with therapists that I am in fact a psychopath in almost every clinically defined sense," he wrote.



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