Best Investigation movies of 1975

Actors : Graham Chapman, Eric Idle, John Cleese, Terry Gilliam,

King Arthur and his knights embark on a low-budget search for the Grail, encountering many, very silly obstacles.

Actors : Gene Hackman, Bernard Fresson, Philippe Léotard, Fernando Rey,
Directors : John Frankenheimer,

"Popeye" Doyle travels to Marseille to find Alain Charnier, the drug smuggler who eluded him in New York.

Actors : Jennifer Warren, Gene Hackman, Harris Yulin, Edward Binns,
Directors : Arthur Penn,

Los Angeles private detective Harry Moseby is hired by a client to find her runaway teenage daughter and he stumbles upon a case of murder and artifact smuggling.

Actors : Gabriele Lavia, Daria Nicolodi, David Hemmings, Macha Méril,
Directors : Dario Argento,

After witnessing the murder of a famous psychic, a musician teams up with a feisty reporter to find the killer while evading attempts on their lives by the unseen assailant bent on keeping a dark secret buried.

Actors : Joanne Woodward, Paul Newman, Murray Hamilton, Anthony Franciosa,
Directors : Stuart Rosenberg,

A big-city private detective travels to the Deep South to help out an old girlfriend who is worried that her husband will find out that she is cheating on him.

Actors : Marty Feldman, Gene Wilder, Madeline Kahn, Dom DeLuise,
Directors : Gene Wilder,

The younger brother of the consulting detective tries to steal Sherlock's glory by solving an important case assisted by an eccentric Scotland Yard detective and a lovely but suspicious actress.

Actors : Mel Ferrer, Judy Geeson, Richard Attenborough, John Wayne,
Directors : Douglas Hickox,

Chicago police lieutenant Jim Brannigan is sent to the UK to escort organized crime boss Ben Larkin back to the USA but Larkin's hit-men prepare an ambush for Brannigan.

Actors : Don Knotts, Susan Clark, Tim Conway, Bill Bixby,
Directors : Norman Tokar,

Three orphan children strike gold in 1878 California.

Actors : Joe Don Baker, Martin Balsam, John Saxon, Linda Evans,
Directors : Andrew V. McLaglen,

A sleazy, incompetent detective tries to simultaneously take down heroin dealers and a socialite who murdered a burglar.

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 : D'Urville Martin, Rudy Challenger, Pam Grier, Austin Stoker,
Directors : William Girdler,

A Chicago private detective returns back home to Louisville, Kentucky, to help her father fight mobsters.

Actors : Edwige Fenech, Nino Castelnuovo, Femi Benussi, Solvi Stubing,
Directors : Andrea Bianchi,

When a fashion model dies during an abortion, a series of murders begins, starting with her doctor. The next victims are connected to the modeling agency where she worked, Albatross, run by...

Actors : Ben Johnson, Paul Winfield, Burt Reynolds, Catherine Deneuve,
Directors : Robert Aldrich,

At the instigation of a grieving father, a Los Angeles cop investigates the suspicious circumstances of a girl's apparent suicide.

Actors : Jean-Louis Trintignant, Claudine Auger, Renato Salvatori, Alain Delon,
Directors : Jacques Deray,

This movie depicts the authentic story of the hunt for the dangerous criminal Emile Buisson, who escaped from prison in 1947. During three years Buisson manages to hide from detective ...

Actors : Lee Patrick, George Segal, Lionel Stander, Stéphane Audran,
Directors : David Giler,

The son of famous detective Sam Spade carries on the family tradition of getting involved with the Maltese Falcon - and with the people who will stop at nothing, including murder, to get it.

Actors : Hector Elizondo, Susan Blakely, Michael Moriarty, Yaphet Kotto,
Directors : Milton Katselas,

Police officer Patty Butler, alias "Chicklet," is the live-in girlfriend of Thomas 'Stick' Henderson to gather evidence. Detective Bo Lockley is instructed to try to find her, not knowing she's also a cop.

Actors : María Kosty, Víctor Petit, Sandra Mozarowsky, José Antonio Calvo,
Directors : Amando de Ossorio,

In this final installment of the Blind Dead series, a doctor and his wife move to a small inhospitable coastal village where he plans to start a practice only to discover that undead demon-worshiping Templar Knights haunt the place.

Actors : Cristina Galbó, George Hilton, Antoine Saint-John, Femi Benussi,
Directors : Luigi Cozzi,

Giorgio is a greedy adulterer who makes a deal with a serial killer to dispose of his wealthy wife, Nora. Unfortunately, a thrill-seeking young couple steal the killer's car with Nora's ...

Actors : Mimsy Farmer, Ray Lovelock, Barry Primus, Carlo Cattaneo,
Directors : Armando Crispino,

A pathology med student and a priest team up to investigate a wave of suicides blamed on sun spots and discover a number of them to be actual murders.

Actors : Shirley Washington, Trina Parks, Edna Richardson, Bettye Sweet,
Directors : William Witney,

Syreena must investigate the disappearance of her mother, Cinderella. A series of wild complications follow.