A Red Deer RCMP constable now faces a new assault charge, which is on top of three others in an unrelated case that are already working their way through the court system.

Const. Eric Pomerleau was charged Tuesday in relation to a drunk driving arrest made more than two years ago.

RCMP officer Eric Pomerleau now faces a total of four charges in two separate cases. (CBC)

Pomerleau was caught on video punching Cory Nielsen and throwing him to the floor at the Red Deer RCMP detachment on Dec. 17, 2012.

The confrontation happened after Pomerleau said he saw Nielsen run a red light. Nielsen was originally convicted of impaired driving and resisting a peace officer, but those convictions were later overturned on appeal.

In issuing his appeal decision, Court of Queen's Bench Justice John Little remarked on the excessive use of force by police the night of Nielsen's arrest.

RCMP found no reason to discipline Pomerleau after the incident involving Nielsen.

Constable on administrative duty

But last November, a formal complaint was lodged against Pomerleau, and he has now been charged with assault in the Nielsen case.

After CBC first reported the Nielsen story in 2013, the young man's lawyer was contacted by a second lawyer who had a videotape of Pomerleau using force on a teenager in custody.

Pomerleau was seen on that video entering a police cell at the Red Deer detachment on Aug. 19, 2012, to confront the teen before throwing him to the floor. After the altercation, the teen was left lying on the floor motionless.

Pomerleau appeared in court last month to face charges of assault with a weapon (pepper spray), assault causing bodily harm and common assault in relation to that case.

RCMP have said the constable is now performing administrative duties at another detachment in Alberta.