The problems began when workers at a local Jack in the Box asked a police officer to help remove a man from the business. The man, later identified as Daniel Bald, had personal items spread out in a booth even though he hadn't purchased anything.
The officer walked up and asked him to leave, and that's when witnesses say Bald turned violent.
"I saw a gentleman trying to stab a bike police officer," said witness Kekoa Chin-Hivano.
The officer said Bald jumped up from the table and repeatedly stabbed him in the chest with a pen. The officer's ballistic vest stopped the pen, and the officer wasn't injured.
After being attacked, the officer made a tactical decision to run outside, leaving the attacker inside with customers as he called for backup.
Some customers at the restaurants are upset by that decision.
"With all his training, and then just to decide, 'Oh, I'm not going to use this,' and just leave all these innocent people?" said Isaiah Tarver.
In his report, the officer readily admits he ran from the man, who briefly followed him outside before returning to the restaurant.
Police say Bald has mental illness issues and they say the officer's decision was appropriate, even though customers were inside.
"Based on my experience, being in uniform, dealing with someone who's mentally ill actually can make them much more uncomfortable," said Det. Sgt. Sean Whitcomb with the Seattle Police Department.
A wall of windows presumably allowed the officer to monitor the situation as it unfolded inside, and his report makes no mention of the attacker threatening anyone else.
"Having that area of space where they are a little bit more settled was the best option," Whitcomb said.
While none would go on the record, some officers say that scrutiny by the Department of Justice over use-of-force complaints has had a chilling effect on the way some officers handle potentially violent situations.
All Seattle police officers have or will soon have training on how to deal with people suffering from mental illness to keep tense situations from escalating.
No customers were hurt in the incident.