So, the OR state police were guarding the outside of the Portland fed buildings.
They arrested people for rioting etc.
The DA said he would not prosecute people for rioting, interfering with police, and such.
If the police order a crowd to disburse the crowd can just say no.
So the OR state police said they would withdraw.
https://www.washingtonexaminer.com/news/district-attorney-to-drop-charges-against-hundreds-of-portland-protestersA new policy from Multnomah County’s top prosecutor stated that only rioters involved in "deliberate property damage, theft, or force against another person or threats of force" could face charges.
https://news.yahoo.com/oregon-state-police-leaving-portland-010925234.htmlOregon State Police leaving Portland over lack of prosecutions
Reuters Reuters•August 13, 2020
(Reuters) - Oregon State Police on Thursday said they were withdrawing protection from Portland's federal courthouse over frustration at the county district attorney's decision not to prosecute most of the people arrested in protests there.
Oregon State Police are "continually reassessing our resources and the needs of our partner agencies and at this time we are inclined to move those resources back to counties where prosecution of criminal conduct is still a priority," OSP spokesman Timothy Fox said in a statement.
The police force is angry at Multnomah County District Attorney Mike Schmidt’s decision not to prosecute many people detained during weeks of protests at the courthouse, Fox said.