Due to the TV show (which distorts reality), there is an artificially increased interest in NCIS; therefore a larger applicant pool (few of which will be hired). A Bachelor's degree is required for federal special agent positions (very few exceptions). Any major is acceptable, but Criminal Justice, Computer Science, Sociology, or Psychology may stand you in better stead. Those meeting the minimum requirements may not compare well to the best qualified applicants, and there are always more applicants than positions. The FBI likes lawyers and accountants, but they hire from various backgrounds, with at least 3 years of substantive employment (http://www.fbijobs.gov/). Any responsible employment is acceptable, but law enforcement may be beneficial. Other federal agency job announcements should be available at https://my.usajobs.gov/login.aspx.
The FBI in particular needs people capable of investigating major frauds and conspiracies involving numerous business and technical occupations and professions; whereas, local police are more oriented to street crime. Federal agents must be capable of understanding and communicating at a level above that usually expected from patrol officers.
Federal agencies are looking for people who fit in at all social strata, and the expectations are greater with regard to preparation of reports and affidavits. In my experience, state and local officers have their affidavits written by prosecutors; whereas, federal agents write their own.
I participated in an agency-sponsored Masters program (Customs Office of Investigation) that wherein the major was management, not CJ.
Being a military officer may be advantageous, and military service normally provides veteran preference in the hiring process. Being a practicing attorney or accountant would also place one in a good position. Forensic computer expertise is desirable in almost all agencies. Language capabilities are prized by all agencies.
You are more likely to be successful if you do not restrict yourself to one agency. Moreover, agents get hired from other agencies regularly. If you have proven yourself in one agency, you will have an advantage for FBI hiring. Being a police officer may be helpful, depending on personal performance and agency reputation.
I recommend that people major in psych and minor in CJ (even though I majored in CJ for a BS and PhD, with a Masters in management sponsored by Customs [on government time]). The academic specialization for a graduate degree is not necessarily important, but as I said, management was chosen by the agency I worked for.
GPA (above 3.5 is a plus), testing, physical fitness, work experience, possibly a polygraph, ability to communicate orally and in writing, and graduate degrees are what determine who gets hired. And, I repeat, there are always more applicants than there are positions.
There are numerous special agent positions (see list below, not all have full arrest, search, and seizure authority), in what was and I assume still is the 1811 job series (1810 are unarmed investigators without arrest authority). There are also law enforcement related positions in the Dept of Homeland Security and other agencies, such as inspector positions or Border Patrol agents, that could be open to those with 2 years of college or less. And, there are federal police officers within federal agencies (e.g., Dept of Veterans Affairs, Treasury, Federal Protective Service).
Customs and Border Protection (uniform wearing: Border Patrol Agent, Inspectors [not full authority])
Dept of Def
Dept of State
Dept of Homeland Sec (ICE, TSA)
Dept of Labor
Fish & Wildlife (few positions, many applicants)
Inspector General Offices within other departments and/or agencies
Securities Exchange Commission
Each branch of the Armed Forces: (NCIS [civilian], Army CID [almost all military], Air Force OSI [almost all military], USMC CID [military, subservient to NCIS])
Air Marshals work for the Dept of Homeland Sec, a very boring job (one who did the work likened it to the movie Groundhog Day). Alcohol Tobacco & Firearms (bombing, arson, felons with weapons) is in the Dept of Justice. You might also consider the U.S. Marshals Service. They have two divisions, one is responsible for fugitive investigations, and has the same grade structure as other major federal agencies. Most federal agencies have Inspector General special agents with varying authorities. The State Dept also has special agents, as does IRS (they do tax evasion and money laundering, which is not as boring as it sounds). State Dept agents ride desks overseas, and do protective details (other than heads of state), visa and passport violations in the US. There are even Fish & Wildlife special agents.
My general advice is to apply at as many places as possible, and accept the first offer. Then, if that’s not where you want to be, keep applying. It is not unusual to find former a
Retired fed spec agent (NCIS [when it was NIS], Customs, & finally Homeland Sec [ICE]), crim justice adj professor, TX peace officer certification, TX investigative hypnosis certification, former tactical team member, TX licensed PI, sat on hiring panels for two fed agencies, defensive tactics and firearms instructor for two federal agencies, formerly USMC Military Police officer & enlisted