Around 112,200 Americans worked as criminal investigation officers or detectives as of 2008, according to the U.S. Bureau of Labor Statistics. The demand for investigation officers is projected to increase by 17 percent through 2018. This growth in the need for law enforcement professionals should result in the creation of around 18,700 new jobs for investigation officers.

Types of Duties

Investigation officers conduct inquiries to discover who committed crimes and to gather evidence to prosecute and convict suspects. Officers interview suspects and witnesses, examine evidence and conduct research through computer databases and other sources. Officers write reports based on their findings and are often called upon to appear in court to explain the results of their investigations. While performing their work, officers must follow laws that protect the rights of suspects, such as obtaining warrants before conducting searches.

Requirements

Most law enforcement agencies require investigation officers to meet minimum physical fitness standards to work in the field. Undergoing and passing criminal background checks and psychological tests are typically necessary as well. Some law enforcement agencies also require prospective criminal investigators to take the United States civil service examination. Investigation officers must typically carry a handgun and are required to maintain a license for their weapons. To perform their investigations and file reports, officers need the ability to use database, word processing, e-mail and photo imaging software, explains the Occupational Information Network.

Training

Education requirements for investigation officers vary from employer to employer, but a high school diploma or GED is generally necessary. Approximately 62 percent of officers have a four-year bachelor's degree, reports the Occupational Information Network. Law enforcement agencies usually provide extensive training for new hires. These courses usually last 12 to 14 weeks, explains the U.S. Bureau of Labor Statistics. New officers are typically given basic assignments and may assist more accomplished professionals during their first one to two years of employment.

Compensation

Investigation officers made an average of $65,860 per year as of May 2009, according to BLS. Overall, salaries ranged from $37,960 annually or less for the lowest-paid 10 percent of officers to $99,980 or more to the highest-paid. The U.S. Postal Service and the federal government were the highest-paying employers of officers with average annual salaries of $88,170 and $75,390, respectively. Most law enforcement professionals receive benefits packages that include health and life insurance, paid vacation days and pensions or retirement plans.