Serial rapist Richard Mantha sentenced to 12 years in prison

Richard Mantha, 62, was sentenced to 12 years in prison Thursday for sexually assaulting three vulnerable women between 2019 and 2023.

Justice Judith Shriar imposed the sentence after Mantha was convicted in April of six offences: three counts of sexual assault, drugging one victim to "aggrieve or annoy" her, suffocating and assaulting another with her own cellphone, and uttering threats against a fourth victim. The charges have not been tested in trial beyond the April conviction.

Mantha targeted women who worked in Calgary's sex trade in southeast Calgary, many struggling with drug addiction. The Crown prosecutor Dominique Mathurin had sought 10 to 13 years; Mantha's defence lawyer Justin Dean sought five to seven years, citing Mantha's deteriorating health after he suffered a stroke in May 2024 while in pre-trial detention, leaving him unable to verbally communicate.

Shriar rejected the health argument, noting the stroke occurred after the crimes were committed and that Mantha's condition can be properly managed in prison. "Without denying that Mr. Mantha's physical and communication impairments pose unique challenges for him, the Court concludes he has not met the burden of showing than an otherwise appropriate sentence would have a disproportionately negative impact on him," Shriar wrote.

Mantha has been in custody since his arrest on April 6, 2023, following a large-scale search of a rural property east of Calgary where he had been living in a rented Quonset hut. With credit for time served—five years and three months—he has six years, eight months and 28 days remaining on his sentence. He was also given a lifetime weapons ban and must register as a sex offender for life.

Aimee Ert, the only victim to have her identity publicly released after successfully petitioning the court to lift a publication ban, attended Thursday's sentencing and read two victim-impact statements. Shriar called her account "one of the most moving this court has ever heard," noting it "powerfully explained the significant emotional impacts of long-lasting fear and anxiety, anger."