EDMONTON — An Alberta RCMP officer who admitted he beat a prisoner but said he was stressed out over the murder of four Mounties has avoided jail.

Const. Desmond Sandboe has been given a six-month conditional sentence.

Three months of that will be house arrest followed by three months under a curfew.

The defence was asking for a conditional discharge, while the Crown was pushing for six to nine months in jail.

Sandboe said outside court that he "truly regrets" everything that has happened and said he's been humiliated.

"I just want people to know that I've been painted as a monster, I've been painted as a bully. I'm a good guy, I made a mistake and I just want to apologize."

He also said in the past there have been complaints made about the way he's treated people, but "not to this extent."

Sandboe testified at his trial that he was attacked by a man who was in a cell at the Lac La Biche detachment in September 2009.

But video surveillance showed that wasn't the case and he pleaded guilty to assault.

The beating came more than four years after four Mounties were gunned down near Mayerthorpe, Alta., by James Roszko.

Sandboe's lawyer, Rod Gregory, had argued that his client suffered from acute stress disorder because he was one of the officers called out at the time of the shootings.

Gregory suggested the beating was not premeditated and Sandboe incorrectly thought his victim, Andrew Clyburn, 33, might attack him. Clyburn had been taken to police cells after becoming unruly during a bar fight in which he was injured.

The Crown argued a discharge wouldn't be appropriate, because it was "a sustained beating over the course of 40 seconds." Prosecutor Jason Neustater also pointed out that Sandboe had faced three internal disciplinary hearings between 2003 and 2005.

Sandboe, a nine-year veteran, had already been suspended without pay, which the RCMP said was "an action reserved for the most serious of conduct matters."

"The conduct of this individual member is not only a disappointment to Canadians, it is also very discouraging for all of the men and women who work in law enforcement, and who daily meet and exceed the public's expectation of their police services," Assistant Commissioner Marianne Ryan said in a release Wednesday.

Ryan said an internal code of conduct investigation will resume after the court process ends. Disciplinary actions include a range of measures up to and including dismissal.

The encounter in the Lac La Biche cellblock has also been referred to the Alberta Serious Incidents Response Team, or ASIRT, an independent body that investigates serious injuries or death involving police officers.