Firearm Offenses — Reasonable Cause to Believe Defined is a legal term used to describe when an individual has a “reasonable cause to believe” that a firearm offense has been committed. This is a standard used by law enforcement when deciding whether to arrest a suspect. The reasonable cause to believe standard takes into account the facts and circumstances that are known to the officer at the time of the arrest. The standard of reasonable cause to believe is used for a variety of firearm offenses, including possession of a firearm by a felon, possession of an unregistered firearm, carrying a concealed weapon, and possession of prohibited ammunition. It is important to note that in order for an officer to have reasonable cause to believe that an offense has been committed, the officer must have sufficient evidence and knowledge of the offense. This evidence must be based on facts that have been observed by the officer. In addition, reasonable cause to believe is also used for other types of firearm offenses, such as the illegal transfer of a firearm, illegal possession of a firearm, and the use of a firearm in the commission of a crime.