Jelani Day Cause of Death Revealed as Drowning by Coroner

Jelani Day's cause of death has been revealed.

On Monday, LaSalle County Coroner Richard Ploch shared that the 25-year-old graduate student — who was found in the Illinois River last month — drowned, according to a news release obtained by PEOPLE. While Day's cause of death has been determined, "the manner in which Mr. Day went into the Illinois River is currently unknown," the release states.

Day's body was located after he had been missing for about a month. He was last seen at a cannabis dispensary on Aug. 24 and was reported missing the next day. The coroner identified Day's body "through forensic dental identification and DNA testing and comparison."

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In Monday's news release, the coroner stated that "there was no evidence of any (pre-death) injury, such as manual strangulation, an assault or altercation, sharp, blunt, or gunshot injury, infection, tumor, natural disease, congenital abnormality, or significant drug intoxication.

One day after Day was reported missing, his car was found in Peru, Ill., which is about 60 miles from Illinois State. Officials also found the clothing Day was last seen wearing inside the vehicle.

Bloomington Police Officer John Fermon told PEOPLE in September that Day's case "was unusual" immediately "from a police standpoint."

"Usually when we have missing persons or runaways there is usually a story behind why they ran away," he said. "They might have had marital issues or they just wanted to get away. He was close with his family. He was attending ISU. There wasn't an underlying explanation as to why he went missing."

Fermon continued, "Usually there is an underlying reason why they go missing and there wasn't for Jelani. He just went missing and that is why we are trying to determine the circumstances around him going missing."

The latest development in Day's death comes not long after his family and fraternity issued a plea for the Federal Bureau of Investigation to take over his case. The Nu Epsilon chapter of the Omega Psi Phi fraternity at Alabama A&M University — where Day was an alum — started an online petition to bring in federal authorities in place of the Bloomington Police Department, who are currently on the case.

"This agency has shown the inability to handle a case of this nature," the fraternity stated in a letter addressed to state and federal officials.

Day's mother, Carmen Bolden Day, shared the petition on her Facebook page. She has openly suspected foul play in her son's death, telling ABC News in September that she wants investigators "to use their tools and their resources so that we can find out what happened to Jelani, because he did not disappear into thin air."

Bolden Day also told Good Morning America last month, "Somebody knows something, somebody's seen something and I need somebody to say something."