Tributes have poured in for Brittney McInnes on a Facebook memorial page. (Facebook)The stepfather of a 17-year-old Calgary girl found dead in her home earlier this week has been charged with first-degree murder.

Calgary police announced the charge against Bradley Wade Rietze, 45, on Friday morning.

Brittney Nora McInnes' body was found in her Canaveral Crescent S.W. home on Monday afternoon. Police have not released the cause of death.

"There are specifics in this investigation that we cannot discuss today. The matter is before the courts," said Acting Staff Sgt. Rick Tuza.

Speaking to reporters on Friday, Tuza said a first-degree murder charge doesn't always mean a planned killing.

"Murder is first degree when it is planned and deliberate. It also includes if a murder is committed during another offence." That could include kidnapping and confinement, various types of sexual assault, and threatening a third person, he said.

Stepfather arrested after hospital discharge

McInnes was a popular student at Dr. E.P. Scarlett High School and worked part-time at a Canyon Meadows Rexall drug store.

McInnes' body was found in this Canyon Meadows house on Monday afternoon. (CBC)A few hours before the teen's body was found, police were called to the Canaveral Crescent house and paramedics took Rietze to a hospital. Police had also searched the house earlier that day because McInnes' mother had reported her missing.

"A search was conducted, but Brittney wasn't found at that time. It was shortly thereafter that a family member who had returned to the residence further searched and found Brittney," said Tuza.

The teen had been dead since at least Sunday, he said.

Rietze was arrested on Thursday night after being discharged from a local hospital.

He had been McInnes' stepfather for 13 years and police had never been called to the home for any kind of family dispute, said Tuza.

Calgary police have dealt with "a number of very tragic incidences" in the past year that have a similar thread, he said.

"I don't want to be investigating [these]," he said. "If you see friends or family having issues that may lead to family violence, I would encourage you to contact [the] many social agencies out there … All I can say is call somebody."