The CBI officers probing the matter should be either from Delhi or some other states but not from Uttar Pradesh, Parvin said.
In the letter, she said the officials should not send their report to the CBI but submit it to a court.
A copy of the report should be provided to her, Parvin said.
She said the case should be heard in a special court within a fixed time-frame.
BSP leaders Swami Prasad Maurya and Naseemuddin Siddqui met the DSP's wife.
Maurya said the guilty should be arrested immediately and President rule imposed in UP.