Jacob Hoggard began serving his sentence Friday after Ontario鈥檚 top court dismissed the Hedley frontman鈥檚 appeal of his sexual assault conviction.

The musician鈥檚 legal team said he surrendered into custody immediately before the ruling was delivered Friday, as is typical in criminal appeals.

The Appeal Court unanimously upheld Hoggard鈥檚 conviction despite finding his trial should not have heard the evidence of a psychologist who testified on the neurobiology of trauma.

Hoggard was found guilty in June 2022 of sexual assault causing bodily harm against an Ottawa woman and later sentenced to five years behind bars. He was released on bail hours later, pending his appeal.

Court documents show his lawyers appealed the conviction on four grounds, including that the trial judge erred by admitting the evidence of clinical psychologist Lori Haskell on the neurobiology of trauma.

They also argued the trial judge wrongly permitted prosecutors to argue that the expert鈥檚 evidence supported the credibility of the woman Hoggard was found to have sexually assaulted.

The Crown argued in court documents that the psychologist鈥檚 evidence was properly admitted at trial, and that the trial judge limited Haskell鈥檚 evidence on the neurobiology of trauma to the 鈥渆stablished evidence.鈥�

Prosecutors also argued that evidence was not challenged by the defence during cross-examination, and that the trial judge gave jurors mid-trial and final instructions on it.

The Appeal Court found that the trial judge erred in admitting the expert鈥檚 evidence in part because it risked being misused by the jury to reason backwards that the complainants had experienced a sexual assault.

Though jurors were instructed they could not use Haskell鈥檚 evidence to diagnose the complainants or conclude that their behaviour was consistent with having been sexually assaulted, some questions raised during deliberations suggested jurors were 鈥渄oing precisely what they were cautioned not to do,鈥� the ruling said.

The trial judge reminded jurors the expert鈥檚 testimony played 鈥渁 very small role鈥� in the case and could not be used to explain the particular evidence in the case, the appeal decision said.

鈥淚n my view, the expert evidence was not necessary in this case. A jury instruction alone would provide the necessary guidance and, moreover, would have avoided the obvious risks that later materialized in the jury questions,鈥� Justice Mary Lou Benotto wrote on behalf of the appeal panel.

The judge鈥檚 response 鈥渃orrected the path the jury appeared to be on,鈥� however, Benotto wrote.

Therefore, the court found 鈥渢here was no substantial wrong or miscarriage of justice,鈥� it said in dismissing the appeal.

The three-judge panel found the trial judge did not make any errors regarding the other grounds raised by Hoggard鈥檚 legal team in challenging the conviction.

Hoggard鈥檚 lawyers said they were disappointed with the Appeal Court ruling.

鈥淲hile we maintain that Mr. Hoggard鈥檚 trial was unfair, we respect the court鈥檚 decision,鈥� Megan Savard, Gerald Chan, Arash Ghiassi and Spencer Bass said in a joint statement.

鈥淲e are carefully reviewing the judgment to consider our next steps.鈥�

At trial, Hoggard was found guilty of sexual assault causing bodily harm against the woman and acquitted of the same charge against a teenage fan. He was also found not guilty of sexual interference, a charge that refers to the sexual touching of someone under 16, in relation to the teen.

Prosecutors alleged Hoggard groped the teen after a Hedley show in Toronto in April 2016, then violently raped her in a Toronto-area hotel room later that year after she turned 16. They alleged Hoggard then violently raped the Ottawa woman in a downtown Toronto hotel in November 2016.

The identity of the complainants is protected under a standard publication ban.

The musician, who was charged in 2018, pleaded not guilty to all charges. In his testimony, he acknowledged having sex with both complainants but denied sexually assaulting them, portraying the encounters as consensual one-night stands.

As a result, the case turned on the issue of consent.

Jurors deliberated for six days and twice declared themselves deadlocked on some aspects before pushing forward. In that time, they asked for the court鈥檚 guidance on several legal issues, many of them related to consent.

Hedley, which rose to fame after Hoggard came in third on the reality show Canadian Idol in 2004, went on an indefinite hiatus when allegations of sexual misconduct surfaced. Its last show was in Kelowna, B.C., on March 24, 2018.