There's a lot of reasons to become an investigator: maybe you care about truth and justice, or maybe you are hoping that you'll be another Sherlock Holmes. District attorney investigators conduct investigations, both independently and as part of a larger team. They must have solid intuition, strong initiative, and precise judgment to conduct their investigations. The ability to assess an investigation as "elementary" doesn't hurt, either.
Contact the district attorney's office in your area to determine how much higher education you need for the job. The requirements may be different in certain states, but generally require at least two years of higher education with classes in criminology, police science, public administration, business administration, or fields that closely relate to these.
Verify the work experience required by calling the district attorney's office. For experience, you generally need at least three years of experience as a peace officer with responsibilities that include investigation. Years as a police woman or a soldier can help, but forget about lighter assignments -- like your tenure as as mall security. For licensing, you generally need a valid state driver's license and the equivalent of an intermediary certificate in your state's peace officer training.
Complete at least three years of classes as a police officer: this time will be a lot less fun than the Police Academy movies made it seem. If you do not already have all of the minimum requirements previously mentioned, you must complete them before you can search and apply for district attorney investigator jobs.
Search for jobs. Check with district attorney's offices in the local area, and consult any of your old contacts on the police force who may know of openings. Visit city, county and state websites to scope out openings. Determine which jobs require that you be a local resident: this can allows you to focus on jobs that might be easier to obtain.
Apply for your chosen job. In your cover letter, do the usual song-and-dance about how your specific experiences and education concerning the law make you the best candidate. It doesn't hurt to tug on their heartstrings a bit in your cover letter: emphasize the passion you have for safeguarding the law and ensuring the safety of your family and your community.
Dr. Chris Snellgrove is a writing specialist, and a veteran of everything from a book-length dissertation to a newspaper editor's desk. He has produced work for academic, business, creative, and non-profit endeavors.