Crime scene investigators are professionals who process and analyze evidence that is found at the scene of a crime. They work with other law enforcement professionals to provide information that can identify perpetrators and determine the events that took place at the scene. Investigators work for law enforcement agencies at the local, state and federal levels, where they are either agency officers or civilians.

Duties at the Crime Scene

Analyzing a crime scene is a long process that involves multiple steps. CSI technicians must secure a crime scene in order to prevent evidence contamination. They then work with other personnel, such as forensic photographers, to carefully document the state of the scene and the location of evidence. Evidence must be photographed and mapped before its removal for analysis. During evidence collection, the technicians follow protocols such as wearing gloves in order to protect the integrity of the chain of evidence. CSI technicians document, collect, tag and seal all items in preparation for moving it to a lab facility.

Crime Lab Duties

Some agencies use CSI technicians or scientists for both crime scene investigation and lab analysis of evidence. In this case, the technicians follow the evidence to a lab facility, where it is analyzed using a variety of scientific methodologies. Trace evidence, such as fibers, paint chips, dirt or glass, is examined microscopically and subjected to chemical testing to determine its origins or makeup. Scientists can extract DNA from samples of body fluid or tissue to determine whether or not the tissue originated from a given individual. Evidence from firearms may be examined in the lab or sent to a ballistics specialist for further testing.

Educational Requirements

Educational requirements for CSI technicians varies according to the individual agency, but in general applicants must possess at least a bachelor's degree. Classwork in social and physical sciences, criminal law and psychology are helpful for entry-level positions. Advanced positions, such as crime scene investigation or lab scientist, require a master's degree in a physical or life science. Individuals may also choose to obtain additional training or certification in a forensic specialty such as ballistics or blood spatter analysis through university or agency programs.

Job Outlook and Employment

The U.S. Department of Labor's Occupational Outlook Handbook estimates that jobs in the field of forensic investigation will continue to grow at a greater than average rate throughout the next decade. The salary for a crime scene investigator varies greatly from job to job. While a local police department may start individuals out at between $30,000 and $40,000, an investigator for a larger agency may expect to make up to $100,000. Most jobs are in urban areas. Although there are many positions available, the competition for these jobs will be steep as more individuals enter the field of crime scene investigation and forensics.

Working Conditions

Crime scene investigators work under various conditions, in both indoor and outdoor settings. Because crimes can occur any time of the day or night, they can expect to work odd, and sometimes long, hours and to have some nights of on-call duty. Many agencies do not hire civilian CSI workers, meaning that they hire from their pool of police officers or agents, and individuals must meet all of the physical requirements for that position. Crime scene investigators are also expected to testify in court regarding their findings and should have good communication skills.