The union representing the courthouse constable who shot a teenager in the Maniwaki courthouse says the situation was inevitable.

Franck Perales, the head of the union representing courthouse constables, said he believes the incident, which took place Wednesday afternoon in the courthouse about 130 kilometres north of Ottawa, would not have happened had the security officer not been on the job ‘alone.’

Perales said constables have long complained they are short-staffed and under pressure.

A video filmed by a witness and posted on Facebook shows an altercation in which a courthouse officer tries to subdue an unruly 18-year-old man by placing him in a headlock.

He refused to submit, so the security officer then asked for help from his colleagues and to call for police.

Several other employees came the court constable's aid but the struggle continues as both men move into another room.

In the video, filmed by a friend of the young man, there is a lot of commotion, shouting, and then a shot is fired.

Perales said that the teenager was at the courthouse to receive a sentence, and after receiving it, wanted to go for a cigarette. He wasn’t permitted to, and that’s how the scuffle began.

In a statement Quebec's bureau of independent investigators (BEI) said that the young man seized a baton from the court security officer and hit him on the head. The court security officer then shot the young man, striking him in the face.

Perales spoke briefly to the constable involved in the altercation Thursday. Since the incident is under investigation, hecould not reveal many details, but said staffing at these smaller courthouses is determined according to how busy it’s expected to be that day.

In this case the constable was alone.

Perales said drawing a weapon is a last resort when security officers fear for their lives.

“He was afraid for his life. If you receive a baton in the head, it is very dangerous. A second time – if you receive another hit in the head, you can die,” he said. “The guy charged a second time in the direction of the constable. He didn't have a choice to protect his life.”

Sureté du Quebec Sgt. Marc Tessier said the injuries sustained by the two were deemed serious.

The teen's friend said the shooting victim was struck near the eye and the bullet lodged in his neck.

On Thursday the BEI said the court constable was expected to survive.

In several posts on social media, a woman identifying herself as the shooting victim's mother said her son is in a medically-induced coma and that he did not suffer any brain injury, and is now recovering.

The mother said her son was in court to be sentenced to six months in jail, and has added that she wants justice for her son.

Quebec Justice Minister Stephanie Vallée said this situation is unique.