One way departments maintain the public's trust is by appropriately vetting applicants and volunteers before bringing them on board. Background checks are a key part of that process. 

This thorough article details what's involved in background checks: 

• Overview of the process 

• Notice and authorization 

• Social security validation and verification 

• Personal references 

• State criminal and felony records 

• County criminal 

• Driving records (also called motor vehicle reports or MVR) 

• Educational verification/professional license verification 

• Sex offender database 

• Compiling the completed record

Source: FireRescue1

Read the article here.