By Robert Phillips 
Deputy District Attorney (ret.) 

• Case Law and Legal Concepts 
• Use of deadly force and qualified immunity 
• Use of deadly force and the failure to warn 
• Deadly force used on mentally disturbed person 

Rule: The use of deadly force against a person armed with a knife, where no attempt to use the knife offensively is made and nothing is done by officers to de-escalate a potentially volatile situation, will subject the officers to potential civil liability. 

Facts: Katy Nolan, of Seattle, Wash., lived with her mentally unstable and physically abusive boyfriend, Ryan Smith. On April 14, 2019, Seattle police responded to their apartment after Nolan report that Smith “was being abusive.” The police talked with Smith, who told them that he suffered from depression, took medication, but was not suicidal. That incident was temporarily resolved by Nolan leaving their apartment to stay a few nights with a friend. Three and a half weeks later, on May 9, Nolan again called police. She reported that Smith, who was armed with a knife, was threatening to kill both himself and her. Nolan was calling from her bathroom, where she had locked herself in as Smith used his fingernails to scrape on the bathroom door in an apparent attempt to terrorize her.  

Nolan also reported ....