"Two of the accused, who have been arrested in connection with this incident, have confessed to their crime during interrogation," Superintendent of Police Atul Saxena told PTI, but refused to identify the men.
He said that in such cases the accused usually resile from their statements in court so they will ensure that there is evidence which can stand judicial scrutiny.
"In most of the cases the accused change their version before the court.... but instead of depending upon their confession we will support the case with concrete evidence," the SP said.
Five accused-- three brothers Pappu Yadav, Awadhesh Yadav and Urvesh Yadav and constables Chhatrapal Yadav and Sarvesh Yadav ---have been arrested in the case that has sparked nation-wide outrage.
The two teenage sisters, who were cousins aged 14 and 15 years, were allegedly gangraped and murdered with their bodies found hanging from a mango tree in a village in Ushait area here.
The girls went missing on May 27 and their bodies were found on May 28 in the district.
Badaun is 300 km from Uttar Pradesh capital Lucknow.