The film stars Udhayanidhi Stalin, Nithya Menen, Aditi Rao Hydari and debutant Rajkumar Pitchumani as the main antagonist with an ensemble supporting cast.

Gautham uses various methods to find the killer with the help of Kamala, a handicapped ex-cop who was previously dealing with the case.

They deduce that the psycho must be a rich man who owns pig farms using the smell from the decayed bodies of the murdered girls.

Gautham, Kamala, and their associates all visit and enquire the owners of pig farms in the area, but they have failed in their attempts.

Unfortunately, the psycho hides himself in a dense area of tall grass and finally manages to kill Rajanayakam.

In the meantime, Dagini manages to go around the psycho's lair and sees a jailed woman and a dead cop's corpse.

However, the psycho begs out to his teacher, where Dagini sees the light in him and places the keys to the cuff a few meters in front of him.

The psycho sees the interview and realizes his mistakes after finally feeling loved by someone, where he jumps off the cliff with a smile on his face.

Mysskin decided to cast Udhayanidhi Stalin in the lead role, despite earlier reports that Shanthanu Bhagyaraj would star.

[4][5] Under the banner of Arun Mozhi Manickam's Double Meaning Productions, Mysskin finalized a cast of Aditi Rao Hydari, Nithya Menon, Rajkumar Pitchumani, and Ram, while Ilaiyaraaja, who worked on the director's previous films Nandalala and Onaayum Aattukkuttiyum, was signed as music composer.

[6][7][8] Principal photography began in early September 2018, with a first look promotional poster released later that month, revealing the title of the project to be Psycho.

[12] The film's first single, titled Unna Nenachu which is sung by Sid Sriram (on his first collaboration with Ilaiyaraaja) and lyrics by Kabilan, was released by director Vetrimaaran on 18 November 2019.

[21] The Hindu wrote "Mysskin’s latest bears no similarity to the 1960 movie, apart from featuring a psychopath at the centre (who, oddly, looks like the terrifying Norman Bates) and the playful macabre tone".