What is it that you don't understand an article from an online dictionary is neither a statute, nor a statement of policy?
You're as pitiful as a schoolboy that screams "you can't do math with letters" because he is ignorant of Algebra.
It's from a legal dictionary, dimwit! It is indeed policy and it has been upheld in the USSC! LOLAY!
Read it and weep, hotshot! http://what-when-how.com/police-science/deadly-force-police/
"deadly force is appropriate if the officer has probable cause to believe that the suspect poses significant threat of death or serious physical injury to officers or others. In addition, the severity of the crime, uncertain conditions or rapidly evolving circumstances, and a suspect actively resisting arrest may enter into the objective reasonableness standard. In other words, the Court views the situation from the officers perspective, evaluating the objective reasonableness of the officers response to the unfolding events."
Your 4 year old has to be more intelligent than you, hotshot. LOL!