11/28/2014 08:42 EST | Updated 01/28/2015 05:59 EST

Philip Grandine recounts 'helplessness' trying to save wife

A few hours after his wife drowned in the bathtub, Philip Grandine spoke with police from Toronto's 41 Division, giving his account of the events leading up to her death. He was later charged with first-degree murder, after investigators found the sedative Lorazepam in her blood.

Investigators allege Grandine, who was 25 and a pastor at the time, drugged and drowned Karissa Grandine so he could continue his relationship with another woman — one of his parishioners. Karissa Grandine, 29, was five months pregnant when she died in hospital.

During the trial's closing arguments this week, Grandine's attorney suggested she might have killed herself or died accidentally.

In the interview, which started at about 2:30 a.m. on Oct. 18 and lasted for about half an hour, Grandine told police he had gone for a run that evening and returned home at 10:45 p.m. to find Karissa unconscious in the tub.

In this excerpt, he describes his failed efforts to get her out of the tub and revive her. Some viewers may find the video interview disturbing.

"It was awful. It was the worst feeling of my life — that is the worst feeling," Grandine says.

"Helplessness," says one of the detectives, off camera.

"It is — it's helplessness," Grandine says.

When paramedics arrived at the scene she was allegedly still in the tub and the water had not been drained.