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Crime Scene Investigator (CSI)

Overview

Crime scene investigators (CSIs) go by many names, including evidence technician, crime scene technician, forensic investigator, crime scene analyst, criminalistics officer and more.

In the past, most CSIs were trained police officers. In fact, most still work out of police stations today. However, the role is increasingly being given to civilians with scientific, rather than law enforcement, expertise.

CSIs spend most of their time in the field, working at crime scenes. The CSI’s job is to:

  • Secure the crime scene
  • Take detailed measurements
  • Sketch and diagram the scene
  • Take photographs
  • Document all evidence taken from the scene (location, nature, etc.)
  • Package and label evidence for transfer to the lab
  • Attend and photograph autopsies
  • Write a report detailing evidence collection procedures and conclusions
  • Testify to their findings in court
  • Maintain equipment and restock portable evidence collection kits

The physical evidence collected by CSIs may include fingerprints, footprints, trace materials, hair and fibers and biological evidence found at the scene and on the victim’s body.

The evidence collected by the CSI is then transferred to a lab, in strict accordance with chain-of-evidence procedures. In the lab, technicians, including forensic chemists, forensic biologists and forensic toxicologists, analyze the samples. CSIs rarely process evidence, unless they have special training in fingerprint processing or blood spatter analysis, for example.

The CSI then prepares a written report detailing how and where all the evidence was collected. CSIs often must testify in court about their findings.

A CSI’s work is often messy, smelly, long and physically demanding. But most CSIs find helping to solve crimes by uncovering the physical evidence rewarding and challenging.

This career profile was reviewed and approved by Max Houck, M.A., Director, Forensic Science Initiative, West Virginia University.

Working Conditions

A CSI must be prepared to work:

  • Long shifts, on call, day or night, on holidays and on weekends
  • Anywhere a crime has occurred, including areas that may be unsafe and/or unsanitary
  • While wearing protective clothing, eyewear, gloves and other safety equipment
  • Carrying heavy equipment
  • In every type of environment, from cramped basements to dense brush to a knee-deep murky pond
  • In all types of weather
  • With body parts, bodily fluids and remains in every state of decomposition
  • Around offensive smells and emotionally disturbing sights
  • With the latest technology – and to continually learn new technologies and methodologies
  • Carefully and methodically, even when under severe time pressures
  • With a wide range of people, including law enforcement, lab personnel and attorneys

Seeing the results of crimes on a daily basis can be emotionally taxing on the CSI. The workload can be overwhelming and the pressure to “work faster” intense. Being on call can take time away from family and friends, leading to burnout.

Academic Requirements

Educational requirements are often set by the hiring agency. Some require a two-year degree, while others demand a bachelor's or even master's degree with extensive study in both scientific subjects and criminal justice.

If you are interested in becoming a crime scene investigator (CSI), start asking questions now. If you want to work as a CSI in a specific city or county, contact the police department or sheriff’s department and ask whether the local CSIs are trained as police officers or civilian CSIs. In many areas, police officers do double duty as CSIs, spending the rest of their time doing police work.

If you decide to train as a police officer, you will likely need several years of experience before you can apply to work as a CSI. 

Think ahead. Most CSIs eventually stop working in the field and go back to police work or transfer to the lab as forensic technicians.

Keep your record clean. CSIs must undergo background checks and, while a perfect record is not essential, you will have to answer for any legal infractions, even traffic tickets.

In High School

  • Take plenty of science courses.
  • Participate in science fairs, creating projects that utilize scientific methods to solve mysteries.
  • Join the debate team to practice public speaking skills and build confidence.

In College

  • Major in chemistry, biology, physics, molecular biology or a related science.
  • Some colleges offer degrees in forensic science. Make sure the program requires at least 24 semester hours of either chemistry or biology and math.
  • Take elective courses in law enforcement, criminal justice and crime scene processing.

After College

  • A master’s degree in forensic science is increasingly required to qualify for jobs in certain jurisdictions. Look for a program that emphasizes laboratory science and research, with coursework in crime scenes, physical evidence, ethics and quality assurance as well as interaction with working forensic laboratories.
  • To become certified, the criminalist must study for and pass an exam administered by the American Board of Criminalistics.
  • Continuing education is required throughout the career.