In real life, the Las Vegas Metropolitan Police Department (LVMPD) Crime Scene Investigators (CSI's) are not detectives and are called Crime Scene Analysts (CSA's). Most present day applicants are surprised to discover that the CSA's so not perform most of the tasks depicted on the series. E.g. They do not interview suspects, they do not write or execute search warrants, and they do not make arrests. In real life they are directed around the scenes by the detectives and supervisors, not the other way around. Detectives are commissioned police officers (sworn personnel). CSA's are civilian personnel, not sworn and do not have the same arrest powers as police officers. However they are very skilled technicians, and are a component of the police response to crime.