Speaking to reporters, Ruchika's family lawyer, Pankaj Bhardwaj said, "The FIR will mention abetment to suicide charges against Rathore."
The lawyer further said the torture of Ruchika's brother by Rathore deeply affected the teenager was one of the reasons for her suicide.
"Ashu could have been a star witness in establishing the suicide abetment angle had the CBI taken up the matter," he added.
This will be the third FIR by the Girhotras against Rathore after a court handed him a six-month sentence in the molestation case.
Home minister P Chidambaram was also unhappy with the way that the Ruchika Girhotra molestation case had been handled over the last 19 years.
"I am unhappy with the way charges have been framed, the trial has been conducted and the accused (Rathore) punished (in the Ruchika case). I am very unhappy," Chidambaram told reporters while presenting his ministry's monthly progress report.