Accused serial rapist had an M.O., Crown argues in similar fact application

Accused serial rapist Richard Mantha's modus operandi involved picking out his victims based on their drug addiction and other vulnerabilities, prosecutor Dominique Mathurin argued Thursday.

Mantha, 61, is on trial in the Alberta Court of Justice, accused of sexually assaulting six women. In some cases, he faces charges alleging he drugged and kidnapped some of the alleged victims.  

Most of the women were working in Calgary's sex trade at the time. All of them were addicted to drugs. 

Mantha was originally accused of targeting a seventh victim, but the woman, who can't be identified because of a publication ban, died in tragic circumstances in December 2023. 

Similarities 'exceedingly generic': defence

On Thursday, the Crown argued the similarities between the evidence of the complainants demonstrates a pattern of behaviour and makes it more likely Mantha committed the crimes. 

Mantha, argued Mathurin, displayed "a pattern of specific conduct — targeting vulnerable women, administering intoxicants to induce incapacitation and engaging in non-consensual sexual activity, that is uniquely and consistently manifested across the complainants' accounts."

But defence lawyer Justin Dean argued the similarities in the evidence are "exceedingly generic, to the point where those features would be common to many if not all allegations of sexual assault."

Dean asked Justice Shriar to dismiss the Crown's similar fact evidence application. 

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Mantha is accused of victimizing the women between August 2019 and April 2023. 

Justice Shriar heard testimony from several of the women who said they were taken to Mantha's rented quonset where the Crown alleges they were drugged and sexually assaulted, often with a vibrator.

• Woman who met 'predator' Richard Mantha through Kijiji ad testifies he drugged, raped her

Mantha is accused of drugging and sexually assaulting one woman in her home for several days after responding to a Kijiji ad for a coffee machine. 

In another case, a woman testified that she discovered she'd been sexually assaulted after an acquaintance sent her a video that showed her being raped allegedly by Mantha for more than three hours.

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Another alleged victim testified she was taken to Mantha's quonset where he attacked her. She said she ran away to the highway but lost consciousness and woke up in the hospital. 

Inadvertent collusion alleged

Police first announced charges against Mantha in March 2023. A month later, two more women came forward and further charges were laid.

Mantha's lawyer argued that Justice Shriar should consider that apparent coincidences or similarities in the women's evidence is potentially the product of inadvertent collusion between the women, some of whom admitted to seeing details of the case in the news. 

Dean also pointed to the fact that two of the women ended up at the same recovery centre together where they were encouraged in group sessions to share their trauma. 

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The prosecution dismissed allegations of collusion. 

"There is no credible evidence that the complaints coordinated their accounts or were influenced by media coverage," argued Mathurin. 

Mantha's trial began in February 2024 but has been delayed several times, first when the accused fired his lawyers and again after he suffered a stroke in May 2024. 

The trial is nearing its end. The case goes back to court in August for Shriar's ruling on similar fact evidence. 

After that, the defence will make its election on whether or not to call evidence. 

And finally, closing arguments will take place.