PORTLAND, Ore. -- The man shot and killed by a Portland police officer Wednesday night was armed with a knife, police said Thursday.

The police bureau identified the man as 24-year-old Terrell Kyreem Johnson.

Police said family members told investigators that Johnson had been struggling with drug addiction before his death and it may have affected his mental health.

Johnson did not have a fixed address and one of his family members had a restraining order against him, police said.

The officer who shot and killed Johnson was Samson Ajir, who was assigned to the transit division. Ajir is an 8-year veteran of the bureau.

The shooting was reported shortly after 7 p.m. on TriMet MAX tracks near Southeast 92nd Avenue and Flavel Street.

Officers were called to respond to a man in his 20s, later identified as Johnson, who was threatening people at the TriMet Flavel Street transit station.

Johnson ran away from police when more officers, including Ajir, arrived at the scene, police said.

The pursuit continued onto a bridge over Johnson Creek on the north side of Flavel Street, where police said Johnson pulled out a utility knife. Ajir was in close proximity of Johnson when he pulled out the knife, police said. That's when Ajir shot Johnson several times.

The state medical examiner said Johnson died of multiple gunshot wounds.

No officers were injured.

Ajir was partnered with a Clackamas County Sheriff's Office deputy, who happened to be his brother, Deputy AJ Ajir, as part of their assignment to the multi-agency Transit Police Division, police said. West Linn Police Officer Jacob Howell assigned to the Transit Division was also near the scene of the encounter.

Officer Samson Ajir was placed on paid administrative leave, which is standard bureau procedure. The Multnomah County District Attorney's Office will present the case to a grand jury.

The case will be presented to the Police Review Board.

Watch: Police give update on shooting