F.I.R movie is about Mohammed Sarkar (Suresh Gopi) who is a cop who takes his job very seriously. He is also a warm family man, married to a smart, loving woman, Laila (Indraja). When he’s assigned to investigate the murder of an underworld don, he finds the odds stacked against him. He ropes in a fellow-cop who’s under suspension orders (Biju Menon), a computer geek (Saikumar) and one of his retired superiors (N F Verghese). The four-man army now goes all out to net the brain behind the crime. They begin to uncover some shocking truths – the man who’s behind the killings is also an arms smuggler, supplying sub-standard weapons to the Indian Army.