Perguntas frequentes

An in-universe answer to this question is never given.

Mac's pin has the letters D and B on it, for Detective Bureau. It is a replica of the pin given to long-term, highly decorated NYPD Detectives. Gary Sinise had asked that his character be given one. Incidentally, Jerry Orbach's Law & Order character, Lenny Briscoe, has one as well.

While often the science and technology portrayed in this series (as well as the other CSI series in the Franchise) are accurate or mirror sound scientific principle, there have been times when methods have led to results simply not possible in the real world. Also whilst the majority of the techniques and technologies used in the CSI franchise are accurate and true to reality, the writers and crew readily admit that they "time cheat". Tests that take seconds in the show often take days or even weeks in real life. Meanwhile the extreme popularity of the CSI TV franchise was credited for a large surge of applications for courses in forensic science; however, many present day applicants are surprised to discover that the CSIs (or Crime Scene Analysts/Crime Scene Technicians, Scientific Investigators etc.) do not perform most of the tasks depicted on the CSI series. E.g. They do not interview suspects, they do not write or execute search warrants, and they do not make arrests. CSIs do not work the way the series portrays them as it would be an inappropriate and improbable practice to allow CSI personnel to be involved in detective work as it would compromise the impartiality of scientific evidence and would be impracticably time-consuming. In real life, the CSIs are directed around the scenes by the detectives and supervisors, not the other way around. Detectives are commissioned police officers (sworn personnel); CSIs 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 force's response to crime.

American law allows for the 'false deception ploy' where the police can claim to have evidence (fingerprints, DNA, CCTV, witnesses) they do not in order to gain a confession, the idea being that any innocent person would know such evidence could not exist and see through it. This has become increasingly controversial however due to cases such as the Central Park 5 rape case in New York where the suspects were told their co-defendants were saying they were responsible so they accused them in turn only to be exonerated years later.

No, they can enter in hot pursuit, to preserve life, to prevent imminent destruction of evidence or to search for a wanted felon. They need a search warrant for evidence when those elements do not apply.