Best Investigation movies of 1970s

Actors : Jean-Pierre Bagot, Roland Amstutz, Michel Albertini, Yves Montand,
Directors : Henri Verneuil,

Conspiracy thriller inspired by the conspiracy theories surrounding the assassination of JFK. After a fictional president is assassinated, a determined, tough prosecutor investigates the emerging conspiracy behind it.

Actors : Jaya Bhaduri, Om Prakash, Pran, Amitabh Bachchan,
Directors : Prakash Mehra,

A tough and honest police officer clashes with a crime boss who, unbeknownst to him, happens to be his parents' murderer.

Actors : Paola Senatore, Janet Agren, Ivan Rassimov, Robert Kerman,
Directors : Umberto Lenzi,

A young woman teams up with an adventurer to find her missing sister in the jungles of New Guinea and they stumble upon a religious cult led by a deranged preacher whom has located his commune in an area inhabited by cannibals.

Actors : Sven Wollter, Carl-Gustaf Lindstedt, Håkan Serner, Thomas Hellberg,
Directors : Bo Widerberg,

Police lieutenant Nyman is murdered in his hospital bed and Martin Beck and his colleagues have another murder to solve. They discover that Nyman was a very tough policeman who received ...

Actors : Manuel Gil, Edwige Fenech, George Hilton, Conchita Airoldi,
Directors : Sergio Martino,

An ambassador's wife discovers that one of the men in her life - either her husband, an ex-lover or her current lover - may be a vicious serial killer.

Actors : Charles Bateman, Strother Martin, L.Q. Jones, Ahna Capri,
Directors : Bernard McEveety,

A family is trapped in a desert town by a cult of senior-citizens who recruit the town's children to worship Satan.

Actors : Barbara McNair, Sheree North, Sidney Poitier, Gerald S. O'Loughlin,
Directors : Don Medford,

In San Francisco, Police Lieutenant Virgil Tibbs helps a group of idealistic vigilantes expose a drug ring controlled by powerful businessmen.

Actors : Gloria Hendry, Fred Williamson, Margaret Avery, Julius Harris,
Directors : Larry Cohen,

A gangster in Harlem must rescue his ex-wife, who has been kidnapped by the Mafia.

Actors : Faye Dunaway, Frank Sinatra, David Dukes, George Coe,
Directors : Brian G. Hutton,

A police inspector, nearing retirement, tracks a serial killer who is terrorizing New York.

Actors : Ray Sager, Wayne Ratay, Phil Laurenson, Judy Cler,
Directors : Herschell Gordon Lewis,

A TV talk-show hostess and her boyfriend investigate a shady magician whom has the ability to hypnotize and control the thoughts of people in order to stage gory on-stage illusions using his powers of mind bending.

Actors : Patrick O'Neal, Mary Woronov, James Patterson, Astrid Heeren,
Directors : Theodore Gershuny,

A man inherits a mansion, which once was a mental home. He visits the place and begins to investigate some crimes that happened in old times, scaring the people living in the region.

Actors : Norman Burton, Dennis Christopher, Tim Thomerson, Gwynne Gilford,
Directors : Vernon Zimmerman,

A shy, lonely film buff embarks on a killing spree against those who browbeat and betray him, all the while stalking his idol, a Marilyn Monroe lookalike.

Actors : Dyan Cannon, Joe Santos, Burt Reynolds, John P. Ryan,
Directors : Buzz Kulik,

New York private eye Shamus McCoy likes girls, drink and gambling, but by the look of his flat business can't be too hot. So an offer of $10,000 to finds some diamonds stolen in a daring ...

Actors : Don Knotts, Tim Conway, Trisha Noble, Bernard Fox,
Directors : Lang Elliott,

This spoof of the Sherlock Holmes stories finds Inspector Winship and Dr. Tart investigating a strange death in a possibly haunted mansion, while dealing with the beautiful heiress and the ...

Actors : Robert Lang, Laurence Harvey, Billie Whitelaw, Elizabeth Taylor,
Directors : Brian G. Hutton,

Ellen Wheeler, a rich woman, is recovering from a nervous breakdown with the help of her husband and a good friend. One day, while staring out the window, she witnesses a murder. But does ...

Actors : Edwige Fenech, Ivan Rassimov, Luigi Pistilli, Anita Strindberg,
Directors : Sergio Martino,

A series of murders are committed near the estate of a degenerate author and his wife.

Actors : Adalberto Maria Merli, Rosy Varte, Jean-Paul Belmondo, Charles Denner,
Directors : Henri Verneuil,

Commissaire Letellier and Inspector Moissac are tracking Minos, a serial killer whose victims are women.

Actors : Anjanette Comer, Marianna Hill, Ruth Roman, Susanne Zenor,
Directors : Ted Post,

A social worker, still reeling from the loss of her architect husband, investigates the eccentric, psychedelic Wadsworth Family, consisting of a mother, two daughters, and an adult son with the apparent mental capacity of an infant.

Actors : Barbara Bouchet, Giancarlo Giannini, Claudine Auger, Rossella Falk,
Directors : Paolo Cavara,

Inspector Tellini investigates serial crimes where victims are paralyzed while having their bellies ripped open with a sharp knife, much in the same way tarantulas are killed by the black ...

Actors : Martin Balsam, Charles Bronson, Paul Koslo, Jack Colvin,
Directors : Michael Winner,

A Los Angeles detective is sent to New York where he must solve a case involving an old Sicilian Mafia family feud.