Home » Degrees and Careers » Crime Scene Investigator

Learn How to Become a Crime Scene Investigator Learn about the many exciting jobs you could have as a crime scene investigator.

crime scene investigators working at crime scene


Crime Scene Investigator Job Description

When a crime is reported, police officers hurry to the scene. They can’t always catch criminals immediately (or alone), though, so they count on other experts for help. Here are some of the many people who play a part in crime scene investigation:

Police OfficersPolice Detectives
Crime Scene Investigators (CSIs)Forensic Science Technicians (Criminalists)
Forensic Scientists (Specialists)Forensic Photographers
Forensic Psychologists

Each one plays a specific role, and has different required (or recommended) education. Let’s look at each one to see what they do at the scene of the crime—or soon after.

Back to top

Police Officers


Police officers are normally the first responders to 911 calls or crime scenes, and they play a very important role. But not all crime scenes are created equal, so they must first evaluate each situation and request the expertise of others, if needed. Vagrancy is a crime, but if a patrol car is alerted to someone sleeping on a city street, police can likely wake him and send him on his way. No need for backup.

Police have a good deal of discretion in their work, and they need to evaluate each situation. They’d have to answer questions like these:

  • Does every publicly intoxicated person need to go to jail?
  • If there’s an altercation between two people, would you need a CSI investigation, or could police handle it alone?
  • When there’s a robbery downtown and the police apprehend the culprit, is there the need for a crime scene investigation, or could the police document what happened for the district attorney?
  • If a homeless mental health patient is angry and swinging a machete, couldn’t officers deescalate the issue, protect the public, and get the man the help he needs?

Obviously, some of these crimes don’t really need a crime scene investigation. On the other hand, when crime scene investigation is needed, police officers are the primary CSIs, but, when necessary, they may solicit the help of other specialists.

Back to top

Police Detectives


When more serious crimes are committed, police officers will cordon off the area, control the movement of people at the crime scene, and limit access of those who don’t belong. This is necessary for the following reasons:

  • To protect people
  • To maintain scene integrity
  • To safeguard evidence

They may then wait for police detectives, who will interview witnesses and suspects, and may arrest guilty parties or request search warrants to follow up on leads. If there are no suspects, they will also gather facts and collect evidence in an effort to find the person or people who committed the crime and bring them to justice.

Police detectives also have specialties, and some of the most common ones are listed below:
Domestic Violence K-9 (Canine)
Forensics Narcotics
Gangs SWAT
Homicide Vice
Internet Crime

To become a police detective, you’ll first need to be a patrol officer and work for a specific amount of time (that’ll depend on your department). You’ll then tell your commanding officer that you’d like to be considered for a promotion, get additional training, take a test, and decide which unit you’d like to be a part of.

When considering what education will help you achieve your career goals, you should remember that a college degree may be beneficial for police detectives, especially a degree in criminal justice.

Back to top

Crime Scene Investigators

Crime scene investigators (CSIs) are those police officers who specialize in gathering evidence (although they can sometimes be civilians). Often, specialized CSIs will find a small clue—a spot of blood, a tire track, a fingerprint—that will lead them to a suspect. That’s what CSIs do: they look for useful evidence that will prove someone’s guilt and stand up in a court of law.

Crime scene investigators collect and preserve this evidence, and diagram, photograph, and otherwise document everything they find. The goal of every good investigator is to match evidence to people or other elements, such as vehicles or weapons. They know the proper protocols for collecting all different kinds of evidence:

DNA evidence (sweat, blood, hair, saliva, and skin)Fingerprints

CSIs must always follow a “chain of custody” to protect evidence so that no one tampers with it. If there are any signs of tampering, evidence will be thrown out by a judge, and prosecutors may have a harder time getting a conviction—or have their case dismissed.

Collecting evidence is a two-part procedure:

initial walk-through

An initial walk-through gives an overview of the crime scene, identifies threats to the integrity of the scene and helps the CSI protect any possible evidence. Written and photographic documentation provides a permanent record of this initial state of the crime scene.


Then, the CSI will prioritize the collection of evidence to prevent loss, destruction, or contamination. All team members must ensure the effective collection, preservation, packaging, and transport of evidence.

As you might guess, the job requires close attention to detail, strong scientific and analytical skills, and a curious mind. And if crime scene investigators want to bring criminals to justice, they must be systematic and ethical because any mistakes may compromise potentially important evidence.

Back to top

How to Become a CSI


Most crime scene investigators are police officers. Police officers need at least a high school diploma or GED, but many departments now require a college degree. A degree in criminal justice with a focus in crime scene investigation may give you an edge over the competition and help you get the job you really want.

Police departments will generally require you to complete basic training at their police academy. After that, you’ll need to pay your dues and work your way up to becoming a crime scene investigator.

Crime scene investigators are often promoted to their jobs internally after a certain number of years of patrol work. But some large local, state and federal police departments also employ civilian crime scene investigators.

When CSIs are finished at a crime scene, their work goes to forensic scientists, who analyze the evidence collected.

Back to top

Forensic Science Technicians

Forensic Science Technicians

Generalist forensic science technicians, sometimes called criminalists, perform the duties of crime scene investigators and laboratory analysts.

They collect evidence at the scene of a crime and analyze it in laboratories, and they may specialize in a particular type of evidence analysis, such as DNA or ballistics.

Depending on their specialization, they may be called latent print examiners or forensic pathologists, and they’ll use chemicals and microscopes to analyze evidence. Other specialists use computers to examine fingerprints, DNA, and other evidence. They try to match the evidence to suspects associated with a crime, and their work gives detectives leads to follow up on.

More specialized forensic scientists may have any number of specialties. See below for more details.

Back to top

Forensic Scientists (Specialists)

Forensic Scientists

While forensic science technicians do a lot of laboratory analysis, the field of forensic science is vast indeed, and there are more forensics specialties than most people realize.

All of the following specialists understand how their field intersects with the legal system, and they offer their expertise when needed. So if police officers or detectives require a deeper level of examination, they may get the help of one or more of these forensics specialists:

DoctorsDocument Examiners
LawyersDigital Evidence Experts
Forensic DentistsForensic Psychiatrists
Forensic AnthropologistsEngineers

Back to top

Forensic Photographers

Forensic Photographers

In some cases, CSIs may be the responders taking photographs, but in others, specialized forensic photographers take over and document a scene so that later, everyone knows exactly how it looked when police arrived.

But it’s not just anyone with a camera who can become a forensic photographer; you’ll need to be certified by the Forensic Photography Certification Board.

Here are some of the requirements:

  • You’ll need at least three years of experience working in photography or digital imaging.
  • You’ll be required to complete 40 hours of photography classes in a police academy or college.
  • Then, you’ll need two letters of endorsement from people actively working in forensic photography (and one of them must be from your immediate supervisor).
  • You’ll need to pass a written and a practical test.

Back to top

Forensic Psychologists


Forensic psychologists are full-fledged psychologists who apply their knowledge of the human mind and behavior to legal matters.

They may help lawyers choose jurors, perform psychological evaluations, evaluate competency to stand trial, and more. When you find them at a crime scene, it’s likely that police detectives have asked for their expertise to understand criminal motives or patterns, or evaluate a detainee. They may also evaluate apparent psychopaths or sociopaths.

To become a forensic psychologist, you’ll need a doctorate in psychology. The two most common degrees for psychologists are the PhD (which is more research-based) and the PsyD (which is more practice-based).

Back to top

Crime Scene Investigator Requirements

As you can see, there are many different kinds of crime scene investigators. To become a traditional CSI, you’ll usually need to be a police officer. This means you must be a U.S. citizen and usually at least 21 years old. In addition to taking and passing competitive written exams, you’ll need to meet certain physical requirements:

  • Pass a vision exam
  • Pass a hearing exam
  • Prove physical strength

Police candidates normally also go through a series of interviews and need to take lie detector and drug tests. Previous law enforcement work or military experience is often a plus.

To become a crime scene investigator, you’ll work on the force for a certain period of time and get the training you need to specialize in crime scene investigation. So why not start your career with a degree in crime scene investigation to give yourself a competitive advantage?

Back to top

Crime Scene Technician Education: What You’ll Study

For each different crime scene specialty, you’ll need different training. The most common degrees for general CSIs is an associate’s or a bachelor’s degree in criminal justice with a focus on crime scene investigation. Regardless of which degree level you choose, you’ll likely study many of the same subjects. Some common prerequisite courses are below.

  • Introduction to the Criminal Justice System: this will help you understand policing, legal system, and corrections, which includes parole and probation.
  • Algebra, because math is often an important part of crime scene investigation.
  • English Composition, because all CSIs need to write concise, easy-to-understand reports.
  • Physical and Biological Science, because these are the scientific foundations of the evidence analysis that forensic scientists do.

You’ll then delve deeper into your subject matter, and learn more about gathering evidence and other facets of criminal justice. Here are some of the courses you’ll take:

  • Crime Scene Investigation: you’ll learn how to process crime scenes, collect evidence, and record what you’ve found.
  • Forensic Fingerprint Analysis: fingerprint analysts learn to “read” fingerprints and match prints to ones in the FBI fingerprint identification system, the largest criminal fingerprint database in the world.
  • Forensic Chemistry and Trace Evidence Analysis: depending on your specialty, you may analyze fibers, hair, soil, wood, gunshot residue, pollen, and more.
  • Supervisory Practices in Criminal Justice: some people aspire to management positions in law enforcement agencies. This course will explain techniques for overseeing other criminal justice personnel.
  • Managing Criminal Justice Organizations: if you aim higher than that, you’ll need to learn how to manage not just a group of people, but departments within your organization.

Studying crime scene investigation is fun and challenging, and getting a degree may offer you better job opportunities. If you go to criminal justice school, you’ll see how satisfying it can be to help other law enforcement professionals identify, locate and apprehend criminals. The specific CSI job you choose is up to you.

Back to top

Crime Scene Investigator Jobs

Whether you want to become a crime scene investigator, a crime scene technician, a forensic scientist, or any of the other specialties listed above, police departments from Savanna to Seattle and Long Island to Los Angeles may be looking for a candidate like you.

Do you want to be a generalist or specialize? Your answer will have a lot to do with your own desires and aptitudes, and the needs and resources of the police department you work for.

Back to top

Crime Scene Investigator Salary

Employment and salary information is limited for crime scene investigators because the U.S. Bureau of Labor Statistics (BLS) doesn’t track this specific profession. Job growth and salary data for crime scene investigators and technicians is included with the information for police and detectives.

Here are the median annual salaries* for some of the CSI jobs mentioned above:
Forensic science technicians $60,590
Police and sheriffs $67,290
Doctors $208,000
Detectives $53,320
Lawyers $126,930
Sociologists $86,110
Psychologists $82,180
Information security analysts $103,590

Also, consider that if you work in one of these related fields and supplement your income with forensics or crime scene investigation work, you’ll only be adding to your salary.

So if you’re results-driven, ethical, and would like to help bring criminals to justice by collecting or analyzing evidence, choose one of the crime scene investigations careers you just read about, and get the education you need to set yourself apart from the competition.

*The salary information listed is based on national median salaries, unless noted. Actual salaries may vary greatly based on specialization within the field, location, years of experience, and a variety of other factors. National long-term projections of employment growth may not reflect local and/or short-term economic or job conditions, and do not guarantee actual job growth.

Sources: www.bls.gov, www.kaplanuniversity.edu/criminal-justice/crime-scene-technician-certificate.aspx, www.nij.gov/topics/forensics/evidence/dna/basics/pages/identifying-to-transporting.aspx, www.ovc.ncjrs.gov/sartkit/develop/issues-coc.html, www.fbi.gov/about-us/lab/forensic-science-communications/fsc/april2000/twgcsi.pdf, www.aafs.org/about-aafs, www.fbi.gov/about-us/cjis/fingerprints_biometrics/iafis/iafis, nij.gov/topics/forensics/evidence/trace/pages/welcome.aspx, www.theiai.org/certifications/imaging/requirements.php

Back to top