Justin Blackmon Arrest -- Arresting Officer Did NOTHING Wrong ... Cops Say

The officer who arrested Justin Blackmon did NOT mistreat the NFL star during his marijuana arrest this week ... despite claims that the cop was "aggressive" ... this according to the Edmond PD.

After TMZ Sports posted the dash cam footage showing the Jacksonville Jaguars receiver's encounter with police on Wednesday ... the PD came under fire from people who claim the cop was a "bully" who "overreacted" during the incident in which Blackmon was handcuffed when cops suspected he had weed in the car (For the record, cops say they found 2 blunts).

But the Edmond PD is backing its guy -- telling TMZ Sports the officer "acted in compliance of and according to our policy in regards to how arrests are conducted."

"Placing someone in handcuffs in that situation is a safety issue not only for the officer, but the person involved who could react in a manner that would turn a minor violation into a felonious act."

The EPD notes that Blackmon was "fully cooperative and compliant throughout this incident."