crime scene
Police found bodies of three children at a Texas City apartment complex. In this image, crime scene tape surrounds Santa Fe High School in Santa Fe, Texas, May 19, 2018. Scott Olson/Getty Images

The Purdue University student who was taken into custody following the death of his roommate told police he used a knife to attack the victim, according to a probable cause affidavit filed on Friday.

The incident initially occurred on Wednesday, when police received a call from Ji Min Sha, 22, at around 12:44 a.m. local time from the on-campus dorm McCutcheon Hall.

Upon arrival, officers discovered Sha's roommate Varun Manish Chheda, 20, in a chair with multiple stab wounds and Sha covered in what appeared to be blood.

The affidavit noted that there was "blood spatter on the wall, a pool of blood on the floor, and a folding knife on the floor." Chheda also had "multiple stab wounds and lacerations" to his neck and head.

Sha was then detained and later told detectives that he stabbed Chheda. "Sha said the knife on the floor was his and admitted he used the knife to kill Chheda while he was sitting in the chair where police found him," the affidavit stated.

"Sha said after he killed Chheda he called 911 and remained in the room until the officers arrived and arrested him."

As Sha walked down the hallway of the Tippecanoe County Jail on Friday he said he was blackmailed when asked why he killed his roommate.

Police have yet to share a motive behind Sha's attack on Chheda. However, Purdue University Police Chief Lesley Wiete previously said the stabbing was "unprovoked and senseless."

During the Friday hearing, a 72-hour hold was filed for Sha as authorities continued to investigate the incident. Since the hold excludes weekends and the Columbus Day holiday on Monday, it will end on Thursday.

The Tippecanoe County prosecutor is expected to file formal charges after the hold expires.