To become a police detective in the US, you'll usually start as a police officer: meet the entry requirements (typically at least 21 years old with a high school diploma), graduate from your agency's training academy, then earn promotion to detective after time on patrol. Federal agencies such as the FBI hire investigators directly but may require a bachelor's degree and work experience.
There's rarely a job ad for a brand-new detective in a city police department. BLS is clear on this: because they need law enforcement experience, detectives typically begin their careers as police officers.
Figures come from the Bureau of Labor Statistics (BLS) Occupational Outlook Handbook, read on 26 October 2026. This page covers police and federal detectives, not private investigators.
Detectives in numbers
| Measure | BLS figure |
|---|---|
| Median pay, detectives and criminal investigators (May 2025) | $93,790 a year |
| Median pay, police and sheriff's patrol officers | $76,210 a year |
| Detective and criminal investigator jobs, 2025 | 120,500 |
| All police and detective jobs, 2025 | 824,200 |
| Projected growth, police and detectives, 2025 to 2035 | 3%, as fast as average |
| Openings each year, police and detectives | About 60,100 on average |
Those pay figures are as of October 2026. Detectives earned a higher median than patrol officers.
How to become a detective, step by step
- Meet the entry requirements. You'll usually need to be at least 21, hold at least a high school diploma and pass rigorous physical and personal checks. A felony conviction or drug use may disqualify you. Most states and localities require U.S. citizenship, and federal officers must be citizens.
- Consider college. It's not always required, but many entry-level officers have college coursework or a degree, and some departments require it.
- Pass the hiring process. Expect written exams, interviews, physical tests of vision, hearing, strength and agility, and possibly polygraph and drug tests.
- Graduate from the academy. Training covers state and local law, constitutional law, civil rights, ethics, patrol, firearms, self-defense, first aid and emergency response, followed by on-the-job training.
- Serve on patrol. Officers usually become eligible for promotion after a probationary period.
- Earn promotion to detective. Promotions are usually based on written exam scores and on-the-job performance. In large departments, an officer may be promoted to detective.
Promotion is the step most people underestimate
Here's the part career guides tend to skip. Getting to detective isn't just about serving your time. BLS says promotions are usually made according to scores on a written examination and on-the-job performance. That means the reports you write on patrol, the cases you help build and how you testify in court all feed into whether you get the role.
Detectives typically investigate serious crimes such as assaults, robberies and homicides, and in large departments they usually specialize in one type of crime, such as homicide or fraud. They work cases on a rotating basis until an arrest and trial are completed or the case is dropped.
The federal route
| Requirement | What BLS says |
|---|---|
| Education | Federal agencies such as the FBI may require a bachelor's degree for detectives and investigators |
| Experience for FBI special agents | At least 2 years of full-time work, or 1 year plus an advanced degree (master's or higher) |
| Training | Usually at the Marine Corps base in Quantico, Virginia, or a Federal Law Enforcement Training Center |
| Citizenship | Federal officers must be U.S. citizens |
| Travel | Agencies such as the FBI and Secret Service may need extensive travel, often at short notice |
Knowledge of a foreign language is an asset in many federal agencies, according to BLS.
What the job is like
Detective work can be physically demanding, stressful and dangerous, and officers regularly see the aftermath of violence. Most work full time, paid overtime is common, and shift work is needed because policing runs around the clock. Detectives are required to write detailed reports and keep meticulous records, and preparing cases and testifying in court is part of the job.
Many agencies provide a uniform allowance, extensive benefits and the option to retire younger than the typical retirement age. Some departments pay extra for bilingual officers or those with college degrees.
If you're not old enough yet
Some departments run cadet programs for people who don't yet meet the age requirement. Cadets do clerical work and attend classes until they're old enough to apply. They usually must be at least 18 and have a driver's license. Court work is a big part of the detective role, and our guide to court transcription jobs is another way to see how cases unfold in the courtroom, and this guide to what to wear to court covers the setting from the public's side.
My verdict
If you want to be a detective, plan to be a strong police officer first. Get through the academy, treat every report and court appearance as part of your promotion file, and study for the written exam when the chance comes. Some college helps, and a degree opens the federal route. It's a demanding path, but the promotion carries a clear pay step up and the investigative work many people join the police for.
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Frequently asked questions
How long does it take to become a detective?
You'll need to finish the academy and on-the-job training, then serve as a police officer through a probationary period before you're eligible for promotion. The timing depends on your department.
Do you need a degree to be a detective?
Not always. Police departments need at least a high school diploma, though some require college. Federal agencies such as the FBI may require a bachelor's degree.
How much do detectives make?
BLS reports a median of $93,790 a year for detectives and criminal investigators in May 2025.
Can you become a detective without being a police officer?
For most local departments, no: detectives typically begin as police officers. Federal agencies such as the FBI hire special agents directly if they meet the requirements.
What are the FBI special agent requirements?
BLS says applicants need at least 2 years of full-time work experience, or 1 year plus a master's or higher degree, and federal officers must be U.S. citizens.
How old do you have to be to become a police officer?
Candidates usually must be at least 21. Some departments run cadet programs for people from 18.
How do police officers get promoted to detective?
Promotions are usually based on written exam scores and on-the-job performance, and in large departments officers may be promoted to detective.
What crimes do detectives investigate?
Serious crimes such as assaults, robberies and homicides. In large departments they often specialize, for example in homicide or fraud.
