How to Become a Crime Scene Investigator: Education and Training

By Dr. Matthew Loux and Bryce Loux  |  03/11/2026

Crime scene investigators (CSIs) play a critical role in the criminal justice system, especially because the work they do directly impacts every investigation and trial. These professionals identify, document, collect, and preserve crucial evidence at crime scenes.

Movies and television shows often glamorize this profession. However, the reality of a crime scene investigator's job is much more tedious, scientific, and difficult compared to what is shown on screen.

If you want to pursue forensic science, enjoy solving complex puzzles, and are driven by the notion of justice, then seeking a career path as a crime scene investigator is an intriguing idea to consider.

What Do Crime Scene Investigators Do?

Crime scene investigators are forensic science technicians or practitioners with training to handle physical evidence or other types of evidence at a crime scene. CSIs collaborate with:

• Police officers
• Detectives
• Forensic scientists
• Medical examiners
• Prosecutors

These criminal investigators are similar to crime scene technicians or forensic science technicians. But unlike what is typically shown on television shows, they do not question suspects or make arrests.

A CSI’s job is more scientific and administrative in nature. A large responsibility is to ensure physical evidence and digital evidence are collected in an objective way.

Crime scene investigators also preserve and document the evidence collected to ensure its reliability and ability to withstand legal challenges. The profession puts great emphasis on:

• Accuracy
• Documentation
• Standard operating procedures
• Neutrality

The Daily Work of a Crime Scene Investigator

The duties of a CSI may vary, depending on the employer and jurisdiction (federal or local). However, most CSIs do approximately the same things on a general level, such as:

• Securing and assessing a crime scene
• Documenting the scene
• Collecting evidence
• Maintaining the chain of custody
• Testifying in court

Securing and Assessing a Crime Scene

CSIs ensure that a scene is safe and not contaminated in a way that destroys evidence. This process includes working with police officers to set up boundaries, control access, and document who comes and goes from the scene.

Documenting the Scene

After establishing a crime scene, accurately documenting the scene is a critical part of the job for crime scene investigators. Using photographs, videos, sketches, and detailed notes, they record the scene along with annotations of the scene’s condition, evidence, and surroundings.

Collecting Evidence

CSIs collect various types of evidence, including:

• Blood and other body fluids
• Hair, fibers, and other trace materials
• Fingerprints and tool impressions
• Weapons and ammo
• Digital storage devices 

Each evidence item is packaged, labeled, and logged in accordance with strict procedural protocols.

Maintaining the Chain of Custody

CSIs document the chain of custody for every evidence item. Maintaining this chain is essential to ensure that the evidence is admissible and can be used in a courtroom.

Testifying in Court

Many CSIs must provide expert witness testimony in courtrooms. They commonly describe the collection and preservation of the evidence and respond to questions during cross-examinations.

Skills Needed to Become a Crime Scene Investigator

An effective CSI must have various abilities, including.

• Technical and analytical skills
• An understanding of forensic science
• An attentive eye to minute details
• The ability to synthesize and analyze data to inform decision-making and reconstruct events
• Excellent written and verbal communication skills

Good written communication is a highly important skill for a CSI to possess, since writing clear, factual and comprehensive reports is a necessary part of the job. These reports may be seen in a court case years later.

Similarly, verbal communication skills are equally important. While in a courtroom, CSIs must explain their reports, findings, and technical concepts in ways that the jury would understand. At the same time, they must remain calm while providing answers to attorneys' questions during cross-examination. 

In addition, CSIs must possess a combination of personal traits that allow them to work effectively in demanding investigative environments, such as:

• Emotional resilience to operate in stressful or disturbing settings
• Objectivity
• Strong discretion and ethics
• Self-discipline
• Persistence
• Teamwork and the ability to work independent when needed

Many people may think that CSI jobs are solitary. In fact, it is very collaborative.

A CSI's responsibilities involve working with teams across many agencies (including state and federal) to make sure that the evidence is interpreted as accurately and as effectively as possible. These teams include various personnel such as:

• Detectives
• Forensic scientists
• Medical examiners
• Prosecutors

CSI Tools and Technology

CSIs require technical skills to do their jobs effectively and identify evidence. Their jobs involve the use of both traditional tools and cutting-edge technology, such as:

• Inverse light sources
• Evidence collection kits, especially fingerprint collection kits
• 3D laser scanners
• Drones
• The Automated Fingerprint Identification System (AFIS) database

Do You Need to Be a Police Officer to Become a CSI?

It is not always necessary to be a police officer to become a crime scene investigator. There are two common career paths into the profession, depending on education and agency requirements.

• Law enforcement CSIs – Some CSIs start as sworn police officers, which requires them to undergo police academy training and gain some field experience before they can move into forensic jobs.
• Civilian CSIs – More and more agencies are employing civilian CSIs. Civilian CSIs do not carry a gun or make arrests and are solely focused on evidence collection and processing.

The Steps to Become a Crime Scene Investigator

Becoming a crime scene investigator typically involves various steps. An aspiring CSI will usually:

• Earn a degree in criminal justice or a related field from an accredited institution
• Gain practical experience through entry-level forensic jobs or internships
• Obtain law enforcement experience if required
• Acquire professional certifications to demonstrate technical competency and knowledge
• Apply for available CSI roles and complete required background checks
• Complete on-the-job training and work under the supervision

For many CSIs, starting out as evidence technicians, forensic lab assistants, or property clerks is quite common. These types of entry-level positions are crucial as they can help provide experience and contacts for networking opportunities.

Educational Requirements for Crime Scene Investigators

Employers hiring for entry-level roles generally expect candidates to have a formal education, earning at least an associate degree from a community college or a bachelor’s degree from an accredited institution. Typical areas of study are:

• Forensic science
• Criminal justice
• Biology
• Chemistry

A bachelor’s degree is often preferred by employers, particularly in more competitive job markets. A master’s degree is also useful if an aspiring CSI intends to qualify for leadership opportunities.

Specializations in Crime Scene Investigations

Many CSIs opt for specialization within the field. For example, these specializations require professional certifications and additional training:

• Bloodstain pattern analysis – Reconstructing activities surrounding a crime based on the shapes, sizes, and distribution of bloodstains
• Firearms and toolmark examination – Determining which weapon fired a bullet or left a mark by examining tool and bullet features
• Digital and cyber forensics – Recovering information from digital devices such as mobile phones and computers
• Forensic anthropology and odontology – Examining bones and teeth to recognize and differentiate between human remains

CSIs and Ethics

Crime scene investigators are expected to conduct their work with strict objectivity and impartiality. Evidence must be documented accurately and without bias, as errors or misrepresentation can compromise cases and damage professional credibility.

Crime Scene Investigation Methods

To establish a crime scene, systematic searching ensures that nothing is overlooked. As CSIs are trained in evaluating and employing various scene search approaches, they choose the most applicable investigation method one for site evaluation.

For example, some of these methods include:

• Grid search – Useful for large outdoor areas to ensure thorough, systematic coverage
• Spiral search – Effective when a single investigator processes a crime scene
• Zone search (also known as the quadrant search method) – Commonly used in buildings or areas divided into sections
• Line search (or strip search) – Practical for wide, open areas where investigators move in parallel lines

Preservation of Scene Integrity

Preserving the crime scene and its evidence represents one of the most significant risk areas in an investigation. Risk encompasses even the most minor, well-intentioned errors that could lead to both the exposure and destruction of the evidence.

Several factors can introduce risk during crime scene processing and compromise the integrity of evidence, such as:

• Non-use of gloves and other personal protective equipment (PPE)
• Access to the scene by unauthorized persons
• Cross-contamination between items of evidence
• Exposure in the open environment

The Future of Crime Scene Investigations

Crime scene investigators, with suitable experience and training, can move into roles such as supervisor, consultant, or trainer/educator. Some investigators transition into forensic research or administrative leadership roles. This career path involves less fieldwork in the community but allow them to apply their expertise through research, policy development, and operational support.

Advances in artificial intelligence and DNA analysis will help shape the future of crime scene investigation. Technology will continue to progress, and CSIs committed to continuous learning will continue to be an integral part of the justice system.

The Bachelor of Science in Criminal Justice at AMU

For adult learners interested in pursuing a career path in criminal investigation and protecting the public from crime, American Military University (AMU) offers an online Bachelor of Science in Criminal Justice. This bachelor’s degree program offers courses in criminology, criminal profiling, and ethics in criminal justice. Other courses include criminalistics, constitutional law, criminal law, and the criminal legal process.

To suit the educational interests of students, this criminal justice program has a concentration in digital forensics. Students can take courses in various types of digital forensics as well as cybercrime and computer forensics.

For further information about the B.S. in criminal justice, visit our criminal justice degree program page.

Note: This degree program is not designed to meet the educational requirements for professional licensure or certification in any country, state, province or other jurisdiction. This program has not been approved by any state professional licensing body and does not lead to any state-issued professional licensure.