Portland city officials stood with the police union president and the state's top prosecutor Wednesday to announce that the city and police union had reached a tentative agreement on reforms to address last year's scathing federal investigation, the Oregonian reports.

The police union waived its right to challenge proposed changes to the Police Bureau's use of force and Taser policies -- although it's unclear what final changes the city agreed to make.

But the union retained the right to challenge any reforms that would require officers to give on-scene interviews to detectives after an officer-involved shooting or allow investigators with the city's Independent Review Division to directly question officers. The agreement still must be approved by members of the rank-and-file Portland Police Association and the City Council.

The issue arose after the U.S. Department of Justice found last year that Portland police engaged in a pattern or practice of excessive force against people suffering from or perceived to have a mental illness. The findings followed a nearly 15-month federal investigation.