Rebecca Mammen John is a Senior Advocate at the Supreme Court of India, and works primarily in the field of criminal defence.

She has also been appointed as a Special Public Prosecutor on occasion by the High Court of Delhi, and frequently comments in leading newspapers and the media on issues of criminal justice reform in India.

[1] In 2012, she represented Kobad Ghandy, an Indian Communist writer and political activist, against charges under the Unlawful Activities (Prevention) Act.

[9][10][11] She has also represented Nupur and Rajesh Talwar, who were accused of murdering their daughter Aarushi as well as a domestic worker, Hemraj, in a widely reported case in 2008.

[13][14] In 2015, John represented the families of the victims of the 1987 Hashimpura massacre, in which members of the Provincial Armed Constabulary were charged with killing more than 40 Muslim men.

"[4] In 2017, John represented politicians Kanimozhi Karunanidhi, and Sanjay Chandra of the Unitech Group in the 2G spectrum case, in which they were acquitted by a special court in Delhi.

[33][34] In addition to private criminal defence, she has on occasion been appointed as a Special Public Prosecutor and government counsel in a number of cases.

[47][48] She called Priya Ramani, her friend Niloufer Venkataraman and journalist Ghazala Wahab, Editor of Force Magazine, as witnesses for the defence.

Wahab had accused Akbar of sexual harassment and assault, at the time she was a young journalist working under him, in a piece written in the Wire titled 'M.J.

[49][50] Additional Chief Metropolitan Magistrate Ravindra Kumar Pandey, of the New Delhi District Court, authored a ninety-one page judgment acquitting Priya Ramani of the offence of criminal defamation,[51][52][53] holding that "Woman has the right to put up the grievance at any platform of her choice even after decades.

In 2013, John spoke with Reuters about what she described as "really, really shoddy" Indian police investigation of rape, as well as the lengthy prosecution process in court.

[67] John has critiqued the use of satisfying the 'collective conscience of society' as a ground to justify the application of thee death penalty, stating, "It is an amorphous term.