To recover monetary damages in a civil case where deadly force was used, you need to prove that the police officer’s use of deadly force was unreasonable.  A police officer’s use of deadly force is reasonable if the officer had probable cause to believe that the suspect posed a significant threat of death or serious physical injury to the officer or others. An officer may not use deadly force to apprehend a suspect where the suspect poses no immediate threat to the officer or others.  On the other hand, an officer may be able to use deadly force to prevent a suspect from escaping where the officer has probable cause to believe that the suspect poses a threat of serious physical harm to the officer or others.