Best Investigation movies of 1970s

Actors : Barry Newman, Diana Muldaur, Robert Colbert, Harold Gould,
Directors : Sidney J. Furie,

Tony Petrocelli, a bright young lawyer practicing in the rich cattle town of Baker, becomes embroiled in a murder case.

Actors : Akiko Nishina, Keiko Kishi, Kôji Kita, Kôji Ishizaka,
Directors : Kon Ichikawa,

Kôsuke Kindaichi, a somewhat peculiar private detective, visits a remote town. He meets a police detective and they start to investigate an old unsolved murder. Then some murders happen. ...

Actors : Alice Arno, Norma Kastel, Jack Taylor, Lina Romay,
Directors : Jesús Franco,

A Whodunit from the great! The investigation into the suicide of a young woman found dead at the bottom of a cliff uncovers many lovers of both sexes, including her Brother's sister and her...

Actors : Renato Pozzetto, Max von Sydow, Shelley Winters, Alberto Lionello,
Directors : Mauro Bolognini,

Black Journal (originally titled Gran Bollito) is a 1977 Italian drama film directed by Mauro Bolognini. It is based on the real life events of Leonarda Cianciulli, the Italian serial killer best known as the "Soap-Maker of Correggio".

Actors : Linda Marlowe, Gary Hope, Sean Hewitt, Richard Monette,
Directors : Lindsay Shonteff,

A female private detective, Harriet Zapper, is hired by a rich old man to find his missing children, and becomes involved in counterfeiting and murder

Actors : Yoshirô Aoki, Kai Atô, Yûsaku Matsuda, Asami Kobayashi,
Directors : Tôru Murakawa,

A journalist steals a gun from a cop after killing him and goes on a spree of robbery and murder.

Actors : Midori Fujita, Shin Kishida, Chôei Takahashi, Sanae Emi,
Directors : Michio Yamamoto,

A doctor investigates the murders of several women at a lakeside resort. His investigation leads him to believe that a vampire is responsible for the murders. He sets out to track the vampire down.

Actors : Jennifer O'Neill, Robert Duvall, Patrick Magee, Donald Sutherland,
Directors : Tom Gries,

An insurance investigator romances a wealthy young beauty when he suspects she may be involved in fencing stolen jewels.

Actors : Shin'ichi Chiba, Masaru Shiga, Janet Hatta, Eiko Matsuda,
Directors : Kinji Fukasaku,

A tough-as-nails cop from Okinawa investigates a savage murder in Tokyo's nightlife district. Originally dismissed as a bumpkin, he soon proves more savvy than the local police.

Actors : Preston Pierce, Georgina Spelvin, Susie Ewing, Rosalind Miles,
Directors : Al Adamson,

A team of girls go on a killing spree across the country.

Actors : Elsa Lanchester, Maurice Evans, Ray Milland, John Carradine,
Directors : Georg Fenady,

The murder of a Wax Museum proprietor and some other strange goings-on in the vicinity prompt a police investigator to determine whether the killer is one of the principles who wants to own...

Actors : Anne Jackson, Eli Wallach, George Kennedy, Steve Ihnat,
Directors : Richard A. Colla,

A dying man frames himself for the kidnapping and murder of an industrialist so his wife and daughter can benefit from the reward money. However, his plan goes awry when he is cured!

Actors : Gloria Hendry, Sherry Jackson, Michael Heit, Robert Viharo,
Directors : Don Edmonds,

A bounty hunter in Los Angeles sets out to track down and stop a masked serial killer who murders women by using kung-fu moves.

Actors : Johnnie Hill, Emerson Boozer, Owen Watson, René Van Clief,
Directors : Michael Fink,

The female head of a detective agency is hired by a crime lord to figure out who's taking his action.

Actors : Nancy Kwan, Ross Hagen, Roberta Collins, Maria De Aragon,
Directors : Robert Vincent O'Neill,

An insurance investigator battles Dr. Tsu and her sexy all-girl army.

Actors : Vinod Mehra, Sunil Dutt, Shatrughan Sinha, Sanjeev Kumar,
Directors : Rajkumar Kohli,

A newly married bride disappears after her marriage.

Actors : James Mason, Curd Jürgens, Jean Seberg, Stephen Boyd,
Directors : Romain Gary,

Interpol investigates the freelance killings of drug and porn peddlers.

Actors : Alan Lake, Mary Millington, Glynn Edwards, Gavin Campbell,
Directors : Willy Roe,

Two detectives are drawn into the world of porn, while investigating murders of centrefolds...

Actors : Damiano Damiani, Riccardo Cucciolla, Franco Nero, Mario Adorf,
Directors : Florestano Vancini,

How the Italian Fascist Party managed to turn the physical elimination of a political enemy into a test of strength fundamental for the ascent into the totalitarian regime.

Actors : Rosie Stone, Frank Bannon, Joshua Bryant, Linda York,

Two Los Angeles detectives are assigned to track down and arrest a brutal rapist-murderer terrorizing the city. Their job is complicated by the fact that the killer is able to avoid capture because he can pose as a woman.