Criminal investigators help to solve important cases using information gathered from crime scenes, witness testimonies, interrogations, and searches. Some investigators work in laboratories, analyzing evidence and recreating crime scenes, while others talk to suspects and perform covert surveillance operations. Depending on a person's interests and abilities, there are several paths he or she may take to become a criminal investigator.
A high school student who wants to become a criminal investigator can prepare by taking advanced science, computer, psychology, and English courses. Science classes such as biology, chemistry, and physics are important to introduce students to DNA studies and related subjects pertaining to criminal investigations. A background in psychology allows a student to better understand a criminal's mind and how to put that understanding to use in solving cases and performing interrogations. Computer science courses help prospective investigators become comfortable entering data and performing searches. Students who excel in English classes will have an easier time writing reports and presenting information to judges and other officials.
Some investigator jobs can be obtained upon receiving a high school diploma, though many people choose to pursue college degrees. Those hoping to work in forensic crime labs frequently major in biological sciences to learn about laboratory testing techniques and applications of scientific research. Persons who wish to engage in surveillance or interviewing investigative work typically pursue degrees in criminal justice or police science. In general, a bachelor's degree qualifies a person to work in most police organizations and government agencies. A person who wants to become a criminal investigator at the federal level, or lead an investigative division, may choose to pursue a master's degree in order to improve his or her credentials and academic knowledge of the profession.
Most law enforcement offices prefer to hire criminal investigators with experience in the field. Previous work as a security guard, loss prevention manager, hotel investigator, police officer is helpful when applying to become a criminal investigator. Preference is frequently given to military servicemen and women, who have received expert training on the tools and techniques involved surveillance and investigative work.
One to three years of supervised work are usually required to become a criminal investigator. New investigators typically act as assistants to established professionals, learning more about the job firsthand while performing less essential investigative tasks. Once a person completes the training period, he or she is given the freedom to operate independently and take on more difficult cases.