In a petition filed before the Principal Sessions Court, Ernakulam, Pappu claimed there was contradiction in the findings of the Special Investigation Team which probed the case, which was in focus in the run-up to the assembly elections earlier this year.
He claimed there were differences in the postmortem report and the charge sheet filed before the court regarding the time of the murder.
He also said it was difficult to believe the police claim that the accused Ameerul Islam alone committed the murder of the 30-year-old law student.
The accused has been charged under various sections of the IPC, including 449 (house-trespass), 376 (punishment for rape), 302 (murder) and 201 (causing disappearance of evidence), besides relevant sections of the SC/ST (Prevention of Atrocities) Act. There are 195 witnesses in the case.