Almost everyone in India remembers the Delhi bus rape - known as the Nirbhaya case. 

The horrific events of December 2012, when a young student was gang raped and assaulted as she travelled home from an evening at the cinema, were so shocking, they left a collective scar on the psyche of an entire country.

So when it was revealed that the brutal attack was to be made into a police procedural drama for Netflix, many asked: Why?

For actress Shefali Shah, though, there was never a question that this particular story should be told.

"As a person - as a woman - yes, Nirbhaya was about the sheer loss of light, the pain, the agony," she told the BBC.

"But when I read the script, I realised there was another woman - not a man - who picked this up and fought it through and got justice. She fought for all the women in this country."

That other woman was Chhaya Sharma, then the deputy commissioner of police (DCP) for south Delhi, and renamed Vartika Chaturvedi in director Richie Mehta's seven-part series called Delhi Crime.

She is the star of the show - but that is exactly how it had to be, says Mehta. Without DCP Sharma, he believes, this could have been a very different story.

"To me, it all stems down to the fact that if the female DCP was not the first person to arrive at the hospital and did not get a chance to see this victim, and react the way she reacted, they probably wouldn't have caught these guys," he explains.

"It was her reaction as a human being, as a woman, that marshalled everybody to make this happen."

Anger over the rape spilled out into the streets in 2012

That night is seared on Chhaya Sharma's memory, but as for whether or not there would have been a different outcome had she not been the first high-ranking officer to arrive, she cannot say.

"I don't know that if a male DCP handled it, the case would have been different. I can't really say - it depends on the sensitivity of the officer, male or female," she told the BBC.

"But being a woman, I think it gave some credence to the case. When it's rape, something happens to me - seeing the critical condition the victim was in, it moved me."

Indeed, the viewer is not spared the truth about the condition of the young woman - who had been brutally raped and assaulted with an iron instrument, causing appalling, and ultimately fatal, internal injuries. A doctor's description of the damage inflicted by the men is breathtaking in its horror.

Sharma says that Shah, who plays her alter-ego DCP Chaturvedi in Delhi Crime, captured her reactions perfectly: the need to distance herself and be professional. But under the surface, she was feeling many of the same things people across the nation would feel over the next few weeks.