Jelani Day went missing on Aug. 24. LaSalle County Coroner Richard Ploch says Day's official cause of death was drowning.

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Jelani Day went missing on Aug. 24. LaSalle County Coroner Richard Ploch says Day's official cause of death was drowning. / Bloomington (Ill.) Police

Updated October 26, 2021 at 8:55 PM ET

The LaSalle County, Ill., coroner has released the cause of death for Jelani Day, the Illinois State University graduate student who was found dead in the Illinois River last month, 11 days after he went missing.

Day's cause of death was officially ruled as drowning, said LaSalle County Coroner Richard Ploch in a statement sent to NPR.

However, Ploch says how Day ended up in the Illinois River is "unknown."

"There was no evidence of antemortem injury, such as manual strangulation, an assault or altercation, sharp, blunt or gunshot injury, infection, tumor, natural disease, congenital abnormality or significant drug intoxication," he said.

Ploch adds that the forensic exam of Day's remains was "suboptimal" due to the degree of decomposition and the activity of river predators while his body was in the warm water.

Day's mother rejects the report

Day's mother, Carmen Bolden Day called the report an "insult" to her and her son, member station WGLT reported.

"Jelani was an avid simmer, and an avid swimmer doesn't drown himself," Day said. "Jelani didn't have depression or mental issues. Those are indicative of someone that had suicidal thoughts. That's not what my son had."

Carmen Bolden Day took part in a march on Tuesday in the town where her son's car was found, Peru, Ill., to pressure authorities to keep the investigation going.

Jelani Day's car was found and then his remains

The 25-year-old graduate student had been living in Bloomington, where he aspired to be a doctor. His car was found in Peru, a small city an hour north of Bloomington, two days after he was last seen on Aug. 24.

Police say Day went missing "in unexplained suspicious circumstances."

Day's white Chrysler 300 was spotted in "a wooded area south of the Illinois Valley YMCA," according to Bloomington Police. Inside the car were the clothes he had been wearing when he was last seen.

But nine days after Day's car was found, police discovered his body in the Illinois River — following a search that was triggered by a tip, member station WGLT reported.

Questions remain as to what happened to Day before his body was found.

"It's suspicious or unusual circumstances while he was missing, and then [the car's location was] also, you know, pretty suspicious or unusual, and I've been a police officer 10 years," Bloomington Police public information officer John Fermon told local news station WMAQ-TV on Monday. "That's very unusual to just find a car like that."

News of Day's case gained national attention as his mother urged authorities to pursue her son's case as they did for Gabby Petito, the 22-year-old white woman who was reported missing on Sept. 11.

Petito's remains were found later in a national park in Wyoming.

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