When law enforcement responds to a call that a crime has been committed, careful and deliberate attention is given to the area or victim of the crime. The specialized personnel that investigate crime scenes are often called crime scene investigators (CSI). This term has become synonymous with television programs and the idea that crime scenes can be quickly searched for evidence and that evidence can be quickly processed and a suspect identified. The reality behind this belief is that much of the work at crime scenes is very tedious and can take a very long time to process.

The traditional crime scene investigator would use basic skills of observation and documentation to record and preserve the scene for later use. The more modern-day investigator will likely use traditional methods but also utilizes advanced technology to assist with collection and preservation. Alternate light sources, chemicals, deoxyribonucleic acid (DNA) collection and processing, and large databases of information are just a few of the technologies available today to assist with evidence and investigations.