Expert in sexual masochism testifies at Catherine Campbell murder trial

A psychiatrist who interviewed accused murderer Christopher Garnier says his description of being in a trance-like state following the death of off-duty officer Catherine Campbell is consistent with the symptoms of "acute stress disorder."

Dr. Stephen Hucker testified Wednesday for the defence in Garnier's second-degree murder trial in Nova Scotia Supreme Court in Halifax. Garnier, 30, is also accused of interfering with human remains. He has pleaded not guilty to both counts.

Hucker was also asked to explain "erotic asphyxiation," saying it produces a sexual "high." Garnier testified this week that Campbell died after she asked to be choked and slapped at a Halifax apartment in the early hours of Sept. 11, 2015.

Garnier has said there are many aspects of what happened that night he can't remember, including wheeling Campbell's body in a green compost bin and dumping her near Halifax's Macdonald Bridge.

Hucker said Garnier's memory loss is a possible symptom of acute stress disorder. He also told defence lawyer Joel Pink that the loud noises Garnier reported hearing in his head, tunnel vision and a feeling of panic are also symptoms.

The psychiatrist testified he interviewed Garnier twice, but it was after the period in which he would have been showing symptoms. He has diagnosed Garnier with PTSD. Hucker also interviewed Garnier's girlfriend, Brittany Fraser, and his friend Mitch Devoe.

As for choking for sexual pleasure, Hucker said people can fall unconscious very fast during erotic asphyxiation and give no warning signs before passing out, making it impossible to signal they're in trouble.

Hucker said people who regularly practise this kind of sexual activity typically take safety precautions, including having a partner they can trust.

The psychiatrist's testimony was interrupted Wednesday afternoon by an objection raised by the Crown after he answered a defence question about Garnier's memory loss.

The jury was sent from the courtroom, and eventually instructed to go home for the night, as lawyers and the judge discussed the objection. Details of those discussions are currently banned from publication.

The CBC's Blair Rhodes live blogged from court. Mobile users can read the blog here.