Investigation or Investigations may refer to:

Law enforcement

* Investigation, the work of a detective * Investigation, the work of a

private investigator A private investigator (often abbreviated to PI and informally called a private eye), a private detective, or inquiry agent is a person who can be hired by individuals or groups to undertake investigatory law services. Private investigators of ...

Criminal investigation Criminal investigation is an applied science that involves the study of facts that are then used to inform criminal trials. A complete criminal investigation can include searching, interviews, interrogations, evidence collection and preservat ...

, the study of facts, used to identify, locate and prove the guilt of an accused criminal *

Criminal investigation department The Criminal Investigation Department (CID) is the branch of a police force to which most plainclothes detectives belong in the United Kingdom and many Commonwealth nations. A force's CID is distinct from its Special Branch (though officers of b ...

, the branch of British Police force to which plainclothes detectives belong *

Federal Bureau of Investigation The Federal Bureau of Investigation (FBI) is the domestic intelligence and security service of the United States and its principal federal law enforcement agency. Operating under the jurisdiction of the United States Department of Justice, ...

, the primary investigative arm of the US Department of Justice * Tax investigation

Medicine

Clinical trial Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, diet ...

, an investigation conducted to collect data for new drugs or devices * Investigational New Drug, a category in a USFDA program *

Outbreak Investigation In epidemiology, an outbreak is a sudden increase in occurrences of a disease when cases are in excess of normal expectancy for the location or season. It may affect a small and localized group or impact upon thousands of people across an entire ...

Science and maths

* Forensic science investigation, in fields such as accounting, science, engineering and information technology *

Investigations in Numbers, Data, and Space Investigations in Numbers, Data, and Space is a K–5 mathematics curriculum, developed at TERC in Cambridge, Massachusetts, United States. The curriculum is often referred to as ''Investigations'' or simply ''TERC''. Patterned after the NCTM stan ...

, a K-5 mathematics curriculum

Arts, entertainment, and media

Literature

* '' The Investigation'', a 1959 book by Stanisław Lem * ''The Investigation'' (play), a 1965 play by Peter Weiss

Television

* "Investigations" (''Star Trek: Voyager''), an episode of the television series ''Star Trek: Voyager'' *

Investigation (TV channel) Investigation (formerly Canal D/Investigation'')'' is a Canadian French-language specialty channel. Owned by Bell Media, it primarily broadcasts true crime programming. It originally launched on December 12, 2013. History On August 10, 2011, ...

, a Canadian French-language specialty channel * ''The Investigation'' (TV series), a 2020 six-part Danish TV series *

Investigation Discovery Investigation Discovery (stylized and branded on-air as ID since 2008) is an American multinational pay television network dedicated to true crime documentaries owned by Warner Bros. Discovery. As of February 2015, approximately 86 million Amer ...

, a digital cable channel

Other uses in arts, entertainment, and media

* ''Investigate'' (magazine), a New Zealand current affairs magazine * ''Investigation'' (film), a 2006 Bulgarian drama *

Investigative journalism Investigative journalism is a form of journalism in which reporters deeply investigate a single topic of interest, such as serious crimes, political corruption, or corporate wrongdoing. An investigative journalist may spend months or years res ...

, the practice of in-depth reporting or analysis *

Temporal Investigations "Trials and Tribble-ations" is the 104th episode of the American science fiction television series '' Star Trek: Deep Space Nine'', the sixth episode of the fifth season. It was written as a tribute to the original series of '' Star Trek,'' in th ...

, an agency of the government of the United Federation of Planets in the fictional universe of ''Star Trek''