PORTLAND, Ore. – Police are asking for witnesses of a fatal officer-involved shooting on the Portland State University campus to come forward.

The shooting, involving PSU police officers, occurred during the early morning hours of June 29 on Southwest College Street, between Southwest Broadway and 6th Avenue. Jason Washington, 45, was killed.

More: Man shot, killed by PSU officers

Portland police is investigating. Sgt. Chris Burley said detectives believe there are witnesses who have not contacted detectives.

Anyone who witnessed the shooting is asked to call Detective Rico Beniga at 503-823-0457 or email him at Rico.Beniga@portlandoregon.gov.

Cellphone video shows Washington with a holstered handgun that comes loose during a scuffle prior to the shooting.

Witnesses say as he picked up the gun, campus police shot him.

PSU identified the officers involved in the shooting as Shawn McKenzie and James Dewey. Both have been sworn officers since 2016 and have been placed on paid administrative leave.

Related: Family calls for firing of two PSU officers in deadly shooting

Witness Keyaira Smith told KGW that a fight had broken out outside a bar and campus officers, at first, stood by and watched.

Smith said Washington tried to intervene and de-escalate the fight, which involved a friend of his.

While doing this, a gun holstered on his hip fell out. He went to pick it up and shots rang out, Smith said.

"The guy who got shot was trying to deescalate the situation the whole time," said witness Patrick Dean. "He was feeling pressed by a bunch of people. He told them, 'I have a gun, I’m a licensed carrier.'"

Photos: Student protest over Jason Washington's death