A Mountie in Kelowna, B.C., is on trial for the assault of a pregnant teenager he allegedly punched in the face.

Const. Steve Conlon, a three-year veteran of the RCMP, has been accused of punching 19-year-old Crystal Young in the face during an altercation in February 2009.

"He punched me in the face and threw me to the ground," Young told CTV News after the incident.

The confrontation began when Const. Kent Hall was pepper-sprayed while trying to make an arrest. He shot the suspect in the legs and later pleaded guilty to careless use of a firearm. Hall still faces possible internal discipline.

After the shooting, officers went to a nearby house to search for a woman involved in the incident. While inside, an officer got into an altercation with Young, who was holding a pit bull.

Police say Conlon allegedly struck her in the face after her dog bit him. Young has denied resisting arrest, saying she was just holding back her dog.

At Conlon's trial, two RCMP officers have testified that they didn't see a punch. Const. Alexander Taggart testified Tuesday that he was with Conlon and that the dog was going after his fellow officer.

"I saw it basically go for his arm," Taggart testified.

He says that he turned away at the time of the alleged punch, and when he turned back, Young was on the ground.

The alleged punch wasn't the only unusual feature of the night. The police apparently cuffed everyone in the house without reading them their rights and took them to the police lock-up.

That was "just for the investigation," Taggart testified. "At that time, I don't recall the decision was to lodge them in cells."

He told the court it's unfortunate he didn't ask more questions that night. The whole incident, including the arrests of several people without charge, is part of an internal RCMP investigation.

With a report from CTV British Columbia's Kent Molgat