The dispatcher is trained to find out:
WHERE? Where is the incident taking place? Where is the fire? Where is the crime? Where is the patient? Where are you? Where is the suspect?
WHAT? What is the nature of the call? What are you reporting? What type of crime? What type of fire? Brush, structure, wildland? What kind of illness or injury.
WHO? Who is involved? Who needs an ambulance? Who are you? Who is the suspect?
WHEN? When did this happen? Is it in progress? Did it just occur?
WEAPONS? Are there any weapons involved? Does anyone have access to weapons?
SAFETY FIRST: NEVER place yourself or other in danger. Do not attempt to apprehend or detain suspects.