Uniformed Law Enforcement

• Uniformed police officers earn an annual salary based on rank and experience. These law enforcements professionals perform duties from answering emergency 911 calls to issuing traffic citations. According to the BLS, the average salary for a uniformed patrol officer was $51,410 in 2008. The lowest 10 percent among this population of police officers earned less than $38,850. The highest 10 percent earned $79,680.
  
  

Police Detectives

• Police detectives work in specialized departments, such as homicide and narcotics. These law enforcement professionals investigate crimes by interviewing suspects and witnesses and collecting evidence. According to the BLS, the average salary for police detectives in 2008 was $60,910. Detective supervisors earned an average annual income of $75,490 in that same year.
  
  

State Troopers

• State troopers patrol the highways of their states, investigating accidents, issuing traffic citations and assisting local police forces when called in for backup. State troopers also have a pay system that is based on rank and years of experience. The average salary for state troopers in 2008 was $57,270, according to the BLS.
  
  

Transit and Railroad Police

• Transit and railroad police forces provide protection for U.S. railways and the public transit system. These law enforcement professionals are on hand in case any suspicious passengers are detected or if any suspicious packages appear on platforms. The average income for these law enforcement professionals was $46,670 in 2008, the BLS says.