An officer involved shooting late Saturday night at the Coppermill Apartments near 71st and Yale results in one dead.

"This officer at that moment was afraid for his life and used deadly force," Tulsa police's Leland Ashley says.

The incident started around 9 p.m. when police received a call about a suicidal subject. 

Ashley says police arrived to the scene a short time later and were told the suspect had been chasing his roommate with a knife. 

The roommate was able to make it out of the apartment.

Police stayed outside the apartment for a couple of hours, while the suspect was still inside. 

Ashley says it could be considered a stand-off.

The suspect walked out onto a balcony a couple of times and then would head right back into the apartment. 

Ashley says police observed flames in the kitchen during this time. 

No word if he was trying to set the place on fire.

Things took a turn for the worse around 11 p.m. 

The suspect stepped out onto a balcony holding what appeared to be a long rifle with a scope. 

Ashley says he then pointed the apparent weapon at officers.

"One Tulsa police officer fired multiple shots and struck the individual at least once," Ashley says.  "The individual was pronounced dead at the scene."

When officers entered the apartment they found the gun.

"What was originally thought was an authentic rifle turned out to be a BB gun," Ashley says.

When to use deadly force is a hard decision for any officer to make. 

Ashley says they have just a split second to make life and death decisions.

"You have to imagine that this individual could have a beat on an officer at a distance and could kill one or two officers," Ashley says.  "You don't have to wait for a subject to fire first.  That first shot might be what kills you."

Police haven't released the name of the suspect or the officer involved in the shooting.

The case will be investigated.

"Ultimately, the case will be presented to the District Attorney's Office," Ashley says.