Three police grab both wrists of man and are unable to effect a takedown until a fourth officer grabs the man around the neck from behind and pulls him to the ground.
Police officer uses a snapdown to control person resisting arrest. He initially grabbed the wrist only to prevent escape, then clinched and executed a snapdown, controlling the man with transitions and body positioning on the ground.
A police officer struggles to arrest a man by wrist control alone. Two bystanders intervene and clinch with the man around the upper body. One of the former bystanders transitions to control the legs, and together execute a very effective takedown and control of the man. Throughout the takedown, the police officer continues to attempt some kind of wrist/arm control.
Complacent police surround man and fail to maintain a safe distance or keep their weapons ready. The man is able to close the distance and stab multiple police, possibly killing one before he is finally shot.
Pain compliance (OC spray and baton) are ineffective against this man, and the police involved lack the skills/ability to physically control him. Backup arrives to assist, but it appears that the man could have overpowered the two police officers in the meantime had he decided to.