Howard Richmond testifies he was acting out sex role-playing game the night he killed wife

Canadian soldier Howard Richmond told a hushed courtroom Friday that he and his wife were acting out a sex role-playing game the night he killed her, and that a loud noise he heard triggered his post-traumatic stress disorder.

Richmond, 53,admitted at the outset of his trial before theOntario Superior Court ofJusticeinOttawa thathe killed 28-year-old Melissa Richmond in July 2013, but he haspleaded not guilty to first-degree murder.

The soldier's lawyers are arguing that their clientisn't criminally responsible because he was suffering from post-traumatic stress disorder and dissociativeflashbacks at the time from his tours of duty.

Richmondtestifiedhe agreed to meet his wife in a ravine next tothe South Keys Shopping Centre to act out a sexual role-playing gamein which he would play a bad man attacking her.

He said hehad been going to the mallas a kind of therapy to acclimatize himself to bustling crowds and noise. And Richmondtestified that while themallmade him nervous and sometimes gave him panic attacks,he agreed to herrequest.

'I felt like I was fighting for my life'

Richmondtold courthe waited in the bushes near the malland that he jumped out at his wifeas she walked by. He testifiedhe was holding a screwdriver whenhe heard a loud noisethat reminded him of his military deployment in Croatia in 1992.

He said he used thescrewdriver to stab his wife, and he criedas he told the courtroom he saw himself doing it.

"I felt like I was fighting for my life," he said.

Richmondtestified he remembered driving home to see if his wifewas all rightand that he knew somethingbad had happened to her. Richmondrolled up his clothes, knife and screwdriver in a bundle, but testified he didn't remember hiding the bundlein the ceiling where police later found it.

He told courthe's "extremely angry" he didn't have the control to stop himself from killinghis wife, whomhe saidwas "the most important thing in my life" and who put up with a lot.

Richmondalso testified Fridaythat while he knew his wife was having an "emotional affair" with another man, he still trusted her.

In the last week of his wife'slife, Richmondhad left the basementwhere he had been sleeping because he felt safer,tostaywith his wifein their master bedroom. He told courttheir sex life had improved after months of low sex drive due to his PTSD.