How do You Become a Criminal Defense Investigator?

When a person has been charged with a crime, it’s after the police have conducted an investigation. There are many times when the investigation has caused the police to arrest the wrong individual. The accused has the right to have their own investigation conducted by professional detectives working for the defense. Defense attorneys can have their own in-house criminal defense investigator to find facts and evidence that will proclaim their clients’ innocence.

Associate Degree Criminal Justice

Criminal investigators can take courses in criminal justice that cover criminal procedures, the correct way to collect evidence and the laws that govern the process. It’s the same course that a police officer would take to join the force. There are courses in constitutional law, profiling and systems of law enforcement along with the general requirements like English and psychology that can help the investigator understand witnesses and write reports.

Bachelor’s Degree Criminal Justice

This degree is meant for higher levels of criminal justice where the student might already be involved in police work or investigations, but want to advance from their current position. The student would delve deeper into the criminal justice degree with courses in homicide investigation, fire investigation and corrections. The courses will depend on the specialty of the student’s choosing. In general, the courses would include sociology, psychology and criminology to understand the complexities of an investigation.


Detectives who don’t work for a police department will likely have to get a certification to prove they can do the work. It’s much like having a license to practice law in a certain state. Even with a degree, lawyers have to pass the BAR exam. There are a few certifications available to the investigator. The National Association of Legal Investigators, or NALI, is a professional organization that tests for competency and issues certifications. The Criminal Defense Investigation Training Council and the International Association for Identification offer certifications too.

Continuing Education

After an associate’s or bachelor’s degree, the investigator can continue their education towards a master’s degree. There are also other voluntary certifications that can help the investigator obtain work with certain types of defense attorneys depending on the lawyer’s specialization. The detective might take a course or two, attend a seminar hosted by law enforcement or gain more knowledge through a mentor.


After completing courses in criminal justice and obtaining a certification, the graduate can work as a criminal defense investigator with a defense lawyer. The investigator should find an established firm that works with lawyers to learn as much as possible before starting their own firm. Private detectives can earn a median income of approximately $48,000 yearly. It’ll depend on experience and where the detective works.

The criminal defense investigator has to be able to talk to witnesses, gather evidence the police might have missed and build a case for the defense attorney based on the evidence available. It requires education on the right way to process evidence as well as how to talk to witnesses. An investigator has to be able to track down leads and evidence without the help of the police who believe they have the correct suspect identified.

See also: Top 10 Best Value Online Bachelor’s Degrees in Paralegal Studies