Final answer:
Law enforcement officers are mandated to arrest the primary aggressor in a domestic violence case and may arrest on charges supported by evidence even if it is not for the most serious suspected crime.
Step-by-step explanation:
When a law enforcement officer determines that a domestic violence battery has occurred, he or she is mandated to take the primary aggressor into custody. This action is based on probable cause that a crime has been committed. In a given scenario, where police apprehend individuals suspected of committing an armed robbery and carrying unlawful weapons, but lack direct evidence of the robbery, officers can still arrest for the offense they can substantiate, which is possession of illegal weapons.
The officers must assess the situation based on evidence and their professional judgment to decide on the next course of action. If the primary aggressor in a domestic violence situation can be identified, it is imperative to detain that individual to prevent further harm and to initiate legal proceedings. In the robbery scenario, despite the lack of direct evidence for the armed robbery charge, the evidence of carrying unlawful weapons provides a clear rationale for custody.