Dr. Todd Grande / 17 min
Solved case
Murder of John Brian Altinger
John Brian Altinger, a 38-year-old Edmonton resident, was lured through a fake dating profile and killed by filmmaker Mark Twitchell in October 2008. Twitchell was convicted of first-degree murder in April 2011.

Background
John Brian Altinger was a 38-year-old originally from White Rock, British Columbia, who was living in Edmonton, Alberta, and working as a quality control inspector at Argus Machine Co. Ltd., an oilfield equipment manufacturer. In October 2008, Altinger began communicating on the dating website Plenty of Fish with a profile that appeared to belong to a woman, but was in fact operated by Mark Twitchell, an aspiring Edmonton filmmaker who had rented a garage to use as a film studio.
The Killing
On October 10, 2008, Altinger told friends he planned to meet the woman he had been chatting with, and he shared with them the address Twitchell had provided. When Altinger arrived at the garage, Twitchell bludgeoned and stabbed him to death. Twitchell attempted to burn the body but was unsuccessful, and subsequently dismembered the remains, placing them in garbage bags that were dumped into a storm sewer near 130th Avenue and 87th Street in Edmonton.
Discovery and Investigation
Altinger's friends grew suspicious after receiving emails purportedly from him stating that his date had taken him on an extended trip to Costa Rica. These emails had in fact been sent by Twitchell after breaking into Altinger's condominium. Twitchell also sent a resignation email to Altinger's employer but did not respond to a request for a forwarding address for Altinger's final paycheque. When friends broke into Altinger's condominium, they found his passport and dirty dishes, with no indication he had packed for travel. This prompted a homicide investigation by the Edmonton Police Service.
Twitchell initially told police he had met Altinger by chance and that Altinger had sold him his Mazda 6 for $40 before leaving for Costa Rica. Police, disbelieving this account, impounded Twitchell's laptop and vehicle, discovering Altinger's blood in the car's trunk. Twitchell was arrested on October 31, 2008, and charged with first-degree murder.
Trial and Conviction
At trial, prosecutors presented a document recovered from Twitchell's laptop titled "SKConfessions" ("Serial Killer Confessions"), which described a narrator's planning and execution of a murder using fake dating profiles as bait, followed by dismemberment and disposal of the body. Twitchell admitted at trial to killing Altinger and authoring the document but claimed he had acted in self-defence, describing the document as fiction based on fact. His interest in the television series Dexter and identification with its lead character were noted repeatedly during the trial, leading some media outlets to refer to him as the "Dexter Killer."
On April 12, 2011, Twitchell was convicted of first-degree murder for Altinger's death and sentenced to life in prison without the possibility of parole for 25 years. Twitchell also faced a separate attempted murder charge related to an earlier attack on another man lured through the same dating website; that charge was ultimately stayed in June 2011 and later dropped following the murder conviction. Twitchell filed a notice of appeal citing extensive media coverage but abandoned the appeal in 2012.
Key facts
- Victims
- John Brian Altinger
- Date
- 2008
- Location
- Edmonton, Alberta, Canada
- Case status
- solved
Case timeline
2008-09
Twitchell shoots a short horror film, House of Cards, at a garage rented in south Edmonton, later used in the killing.
2008-10-10
John Brian Altinger tells friends he plans to meet a woman from a dating site and shares the address; he is bludgeoned and stabbed to death by Mark Twitchell at the garage.
2008-10-31
Mark Twitchell is arrested and charged with first-degree murder of Altinger.
2011-04-12
Twitchell is convicted of first-degree murder and sentenced to life in prison without parole eligibility for 25 years.
2011-06-17
An attempted murder charge against Twitchell, related to a separate attack, is stayed in the Court of Queen's Bench of Alberta.
2012
Twitchell abandons his appeal of the murder conviction.
Best coverage
Titles and descriptions are the creators’ own and may not reflect current legal status; see the dossier above for sourced case facts.
People
Mark Twitchell
CONVICTEDConvicted of first-degree murder on April 12, 2011, for the killing of John Brian Altinger; sentenced to life in prison without parole eligibility for 25 years.
John Brian Altinger
VICTIM38-year-old quality control inspector killed by Mark Twitchell in October 2008.
Roles reflect public records and court outcomes at the time of writing — supporting citations are on file under Sources.
Places
Common questions
- What happened to the victim?
- John Brian Altinger, a 38-year-old Edmonton resident, was lured through a fake dating profile and killed by filmmaker Mark Twitchell in October 2008. Twitchell was convicted of first-degree murder in April 2011.
- Where did the murder happen?
- Edmonton, Alberta, Canada.
- Who was convicted?
- Mark Twitchell (Convicted of first-degree murder on April 12, 2011, for the killing of John Brian Altinger; sentenced to life in prison without parole eligibility for 25 years.).
- What is the current status of the case?
- Status: solved.
Sources
- ENCYCLOPEDICMark TwitchellWikipedia · 2026-07-18
- PRESSContemporaneous coverage — CBC NewsCBC News · 2026-07-18
- PRESSContemporaneous coverage — CBS NewsCBS News · 2026-07-18
Record history
- First published
- JUL 18, 2026
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