Best Investigation movies of 1970s

Actors : Barbara Bouchet, Nino Segurini, Farley Granger, Rosalba Neri,
Directors : Silvio Amadio,

A writer's secretary tries to find her missing friend and uncovers a murder plot.

Actors : Mascha Gonska, Romy Schneider, Philippe Brizard, Michel Piccoli,
Directors : Francis Girod,

A cunning French legal adviser teams up with an unemployed German girl and her sister to commit murders in Marseille.

Actors : David McCallum, Eric Server, Sandra McCabe, George Wyner,
Directors : Burt Brinckerhoff,

A pack of dogs go on a killing spree.

Actors : Victor Izay, Leslie McRay, Tom Pace, Lila Zaborin,
Directors : Ted V. Mikels,

Lorraine and Mark enter the world of witchcraft where Mara foretells the future and helps them remember their past lives. When a series of mysterious murders begin to occur, they turn to Dr. Helsford for advice.

Actors : Mel Ferrer, Lia Tanzi, Claudio Cassinelli, Gianfranco Barra,
Directors : Sergio Martino,

A young prostitute is found brutally killed and is up to detective Germi (Claudio Cassinelli) the investigation of the case, as the search progress he uncovers a girls trafficking ring with connections to powerful people.

Actors : Cameron Mitchell, William Gray Espy, Aldo Ray, May Britt,
Directors : Herb Freed,

May Britt plays a seemingly innocent farm girl convinced that her slovenly uncle (Cameron Mitchell) is the man responsible for the bloody scissor-murders of several local girls.

Actors : Dean Martin, Thalmus Rasulala, Eugene Roche, Denise Nicholas,
Directors : Paul Bogart,

A San Francisco attorney (Dean Martin) is hired to defend a black militant accused of murder.

Actors : Cheri Caffaro, Richard Smedley, Patrick Wright, Laurie Rose,
Directors : Don Schain,

Cheerleaders and models are kidnapped & sold by a white slavery ring. Female agent is sent to rescue them.

Actors : Charles Grodin, Joan Collins, Farrah Fawcett, Art Carney,
Directors : Richard C. Sarafian,

After a rich old man dies in a suspicious car accident in Acapulco, his widow wants his insurance company to pony up $5 million. A hotshot investigator Decker (Grodin) and a charming model (Fawcett) come in to check it out.

Actors : Gwen Arment, William Metzo, Laura Misch Owens, Curt Dawson,
Directors : Jack Weis,

Police try to capture someone who is commiting ritual murders of women during Mardi Gras in New Orleans.

Actors : Diana Lorys, Paul Naschy, Eduardo Calvo, Eva León,
Directors : Carlos Aured,

An ex-convict, troubled by dreams that he strangles women, is hired as the caretaker on an estate owned by three very strange sisters. Soon after his arrival, a serial killer begins ...

Actors : Arthur O'Sullivan, Anton Diffring, Luigi Pistilli, Dagmar Lassander,
Directors : Riccardo Freda,

In Dublin, a young woman is brutally murdered in her home by a maniac that throws acid in her face and then slits her throat with a razor. Her mangled body is later discovered in the boot ...

Actors : Anthony Steffen, Sylva Koscina, Giovanna Lenzi, Renato De Carmine,
Directors : Sergio Pastore,

A blind pianist tries to figure out who is responsible for a string of murders using a black cat with its claws dipped in curare.

Actors : Robert Mitchum, Mike Connors, James Franciscus, Jaclyn Smith,
Directors : Ted Post,

A woman is convinced by her lover to poison her cruel husband, a rich businessman. However, she becomes terrified when she finds the lover dead as well. A sinister PI, who's investigating her husband's disappearance, contacts her.

Actors : Joseph Cotten, Tomas Milian, Maria Fiore, Mario Piave,
Directors : Umberto Lenzi,

A biker's brother is killed while investigating the kidnapping of a young boy, the byproduct of a war between two crime families. The biker vows to get revenge by finding the kidnapped boy and destroying the two families.

Actors : Harold Sakata, George Lazenby, Jim Kelly, Terry Moore,
Directors : Al Adamson,

The Pig has a plan to eradicate some people with a freeze bomb that instantly freezes people to death. It is up to Detective Ash to stop him and protect the woman with the secret to the ice...

Actors : Yi Tao Chang, Lau Chan, Dragon Lee, Lik Cheung,
Directors : Joseph Kong,

John Liu, the legendary Northern Kick expert is sent to investigate an antiques smuggling gang working out of Canton.

Actors : John Wood, Dudley Sutton, Sammy Davis Jr., Peter Lawford,
Directors : Jerry Lewis,

Two night club owners find themselves in trouble with the law. One of them goes to his English Lord brother for help, and the Lord is later murdered. He swaps places with his dead brother to solve the murder.

Actors : Patricia Loran, Orchidea de Santis, Paul Naschy, Renzo Marignano,
Directors : José Luis Madrid,

In this version of the famous story of the London serial killer, Jack not only likes to kill prostitutes but he is a cannibal as well.

Actors : Kayo Matsuo, Atsuo Nakamura, Akira Nakao, Yukiko Kobayashi,
Directors : Michio Yamamoto,

Keiko and her friend are trying to find her missing brother after he disappeared visiting his girlfriend Yuko.