‘Oru CBI Diary Kuripuu’, directed by K. Madhu and written by S.N. Swamy, is considered a trendsetter in the Investigative Thriller genre of Malayalam Cinema and would spark the arrival of many more such movies in its wake.

It introduces the Tamil Brahmin sleuth Sethuraman Iyer, played with elegance and grace by Malayalam Superstar Mammootty, a role he would reprise in many more sequels in subsequent years.

The beauty of the movie’s plot is that the crime investigation takes center stage, and the narrative is built slowly in the context of the crime. Mammootty’s Iyer does not make an appearance until the movie has set the context of the plot. There are no deviations, and barring a few fight sequences, there are few commercial elements, notorious time-wasters in Indian Movies.

The plot begins with the police arriving at an affluent home in a small town in Kerala. They are there to investigate the death of Omana (Lizzy), a woman who lived in the home with her husband Sunny (Sreenath) and her father-in-law Ouseppachan (Janardhanan). Omana seems to have fallen to her death from atop the roof of the multi-storied home and landed on the stone pavement below.

Also present at the home during the police investigation are Ouseppachan’s son-in-law Johnny Kutty (Vijayaraghavan) and Narayanan (Prathapachandran), Ouseppachan’s friend and a failed politician.

The police interrogate each of these men, a servant maid, and a tenant of Ouseppachan who lives nearby. Omana’s devastated father, John Thomas (Bahadhoor), and sister Annie (Urvashi) also arrive at the scene to grieve her demise. Conspicuously absent from the investigation is Ouseppachan’s driver, a local thug who has had brushes with the law.

Ouseppachan, who is a wealthy businessman in the town, exerts powerful influence in the area and does all he can to stall the investigation’s progress.

Much to the vexation of John Thomas and Annie, the investigating officer on the case is replaced by DYSP Devadas (Sukumaran), a corrupt officer who rules the case a suicide and then closes the investigation.

John and Annie do all they can to force the reopening of the case. First, they attempt to gather a crowd and protest, but the police violently stop the effort. They appeal to a local minister, who callously brushes aside their concerns. However, with the help of Chacko, a police constable and nephew of John Thomas, the father and daughter send out letters to the central government.

The Central Bureau of Investigation (CBI), an equivalent of the FBI in India, assigns the case to Sethuraman Iyer (Mammootty), who takes it on. Not finding the proverbial ‘smoking gun’ after a meeting with John Thomas and Annie, he is about to close the case. (Apparently, Iyer is so impressed with Chacko that in sequels to the movie he brings him on as his assistant in future investigations.)

However, after discussing the events and concerns of the case with Chacko, who comes across as an intelligent young man with genuine concerns, Iyer takes on the investigation. He enlists two assistants, Harry and Vikram (Jagathy Sreekumar). Suresh Gopi, who plays Harry, appears only in this first movie of the series. In subsequent years, he too would become a Malayalam Superstar and play the lead in his own thrillers. Vikram is a master of disguise who also adds some comic relief to the plot.

The trio first launches an investigation to unearth the finances and transactions of Ouseppachan and his associates. This effort unearths Ouseppachan’s corruption and provides insights into his efforts to bribe those investigating the crime.

Then the trio reenacts the crime scene by throwing down a dummy weighing as much as the deceased and making measurements and observations. This sort of detailed investigation was a novel addition to Malayalam movies.

While the forensic technology of the 1980s was not even close to what we have today, one can still appreciate the level of detail that the movie went into for this.

For instance, while DNA analysis of blood from a crime scene was yet to be a reality, the CBI team makes use of comparing blood groups as part of their investigation.

After more investigation, Iyer discovers the mystery behind the crime and identifies the killer. I cannot say enough about the movie. The screenplay is slick, and the cinematography is also commendable.

The plot is taut and has few distractions. Besides spawning numerous other great investigative thrillers, ‘Oru CBI Diary Kurippu’ would be the first movie in the CBI Investigative Thriller series featuring Mammootty as Sethuraman Iyer. The story in the movie is told from the vantage point of the crime, the witnesses, the victims, and the investigation. Thankfully it does not waste time on the backstory of the protagonist nor by presenting irrelevant flashbacks.

Each character in the film is simple and realistic. The rich and powerful exerting undue influence on the law and manipulating it for their interests was and continues to be a common occurrence in India.

Do not miss this iconic movie in the Investigative Thriller genre of Malayalam cinema.