The trial to determine if former Mountie Kevin Gregson is guilty of killing an Ottawa police officer resumed Monday with testimony from his ex-wife.

Gregson's ex-wife, who cannot be identified due to a publication ban, testified that on Dec. 28, 2009 she confronted Gregson with allegations of a sexual crime. She says a 10-year-old girl told her Gregson had raped her.

The confrontation happened just hours before Czapnik was murdered. Gregson's ex-wife says Gregson left saying "I'm done" and that the RCMP would be "jumping on this" whether it was true or not. According to his ex-wife, Gregson denied it happened.

The allegations of rape have not been proven and will go before the court at a separate and unrelated trial in September.

The judge warned the jury of this and said to consider the allegation as part of an "unfolding narrative." The jury is not to make any assumptions about his character based on the sex assault accusation.

Last week the courts heard about Gregson's troubled career as a Mountie and how he had been under internal review for years before a decision he resign or be formally dismissed was handed down.

The courts will also hear allegations of a carjacking by Gregson the night before Czapnik was killed.

With a report from CTV Ottawa's Catherine Lathem