The "Jolly LLB" director wanted to set the film in Haryana and decided to include the incident in his story.
"While writing, I wasn't sure what is the thing I want to deal with in the film. I wanted to set the story in Haryana as I knew their humour, jokes and their orchestra. Eventually, I started toying with the idea of setting up the critical scenarios in the backdrop of the film," Kapoor told PTI.
Kapoor, a former scribe, said he went to his journalist friends while researching about the 2007 incident.
"My film is about Guddu and Rangeela and what happens when Baby comes into their lives. The world you will see is a bit of khap panchayat and honour killing. But it would be wrong to say that the film is based on Manoj and Babli case. It's in the backdrop."
It is the second time that Kapoor is working with Arshad after their last hit "Jolly LLB" and the director said the "Munnabhai" star was always the first choice for the role of Rangeela.
"I started working on 'Guddu Rangeela' four years ago. It gets very important for me to have the actor in my mind while writing the script as it makes my work easy. Arshad was the first one to come into my mind."
He cast "Kai Po Che" star Amit Sadh as Guddu in the movie for his gregarious personality.
"I roped in Amit because his characteristics are very similar to Guddu as the character in the film is very similar to him. The character is outspoken, a flirt and a joker."
Delhi and NCR have served as a muse to Kapoor for the third time as it is a world that is familiar to him.
"Delhi is just like coming home. Being in the profession of journalism, I know the bit of world and politics. I know Punjab and Haryana belt also and that's why I am very comfortable in telling my stories set in this world," he said.
Produced by Mangal Murti Films and presented by Fox Star Studios, the movie, also stars Aditi Rao Hydari and Ronit Roy.
'Guddu Rangeela' is slated to release this Friday.