High School

The minimum requirement to be a private investigator is to have a high school diploma. A good foundation for this type of work is classes in business, math, English, and computers.

Postsecondary Education

A bachelor's degree may be required by some private investigation agencies and is particularly helpful in working on cases for corporations, law firms, and financial institutions. A degree in criminal justice or police science is useful. Investigators who work in financial investigation may have a degree in accounting or finance. Computer forensic investigators may have a degree in computer science, and they must stay up to date on the latest technology and software developments.

Certification or Licensing

Most states require private investigators be licensed to practice private investigation. Licensing requirements vary by state. Private investigators who carry handguns must also meet additional requirements. Certification is not required but can enhance skills and demonstrate competence to prospective employers and clients. Private investigators can receive certification through professional associations such as the National Association of Legal Investigators and ASIS International.

Many professional investigators have prior work experience in law enforcement, the military, or federal intelligence. Some may have worked in one of these fields for 20 or more years and moved on to private investigation as a second career. There are also private investigators who start in the field as interns and in entry-level positions and train while on the job. In specialties such as legal, financial, and corporate investigation, investigators may have years of experience as paralegals or accountants. Private investigation work requires strong communication skills to work with different clients and to conduct interviews. Decision-making skills, inquisitiveness, patience, and resourcefulness are required to do this type of work.