The Parkash family waged a much-publicized battle in the courts to get charges filed against Mr. Rathore, and finally, in 1999, the Haryana High Court ruled in their favor.

In January 2000, nearly a decade after the incident, Mr. Rathore was charged with molesting Ruchika Girotra. He faced a sentence of up to two years in prison if convicted. He was placed on leave from the police force.

The trial stretched on for almost another decade. Mr. Rathore’s wife, Abha, a well-known High Court lawyer, defended him. Mr. Girotra said that the defense found endless ways to drag out the trial. There were more than 400 hearings and repeated continuances. Mrs. Rathore cross-examined witnesses for months.

Finally, on Dec. 21, 2009, nearly two decades after the crime, Mr. Rathore was convicted of molesting Ruchika. The judge gave him a reduced sentence of six months in prison after his wife argued that the long trial and Mr. Rathore’s age, 67, entitled him to leniency. He was also fined 1,000 rupees, about $22.

Mr. Rathore is out on bail as he appeals the verdict. Mr. Girotra and his son have filed new charges against Mr. Rathore for his involvement in the son’s arrest and treatment. Now the Girotra and Parkash families want the government to charge Mr. Rathore with a more serious crime, abetment to suicide, contending that he drove Ruchika to her death. That crime carries a 10-year sentence.

The government is planning changes to its criminal procedures in response to the case. Now officers will be required to file charges based on the victim’s statement alone in cases involving sexual crimes, a measure aimed at making it harder to evade investigation. It is also considering fast-track courts to deal with such crimes.

Mr. Parkash said these changes were proof that the people could take on the powerful and win.

“This is a fight against a rotten system,” he said. “We have to do our duty. I will take this case to its logical end, until the end of my life.”