reporters.
The Jackson State University student had also suffered a non-fatal gunshot wound to the leg.
An autopsy showed he was alive when he was beheaded.
FINAL MOMENTS He was last seen on June 9, 2017, the day before his body and head were found.
Corey said his brother was in good spirits. He'd given him a hair cut before driving him to an interview at a restaurant, which he'd been offered.
He said he "didn’t seem worried or scared like something was going to happen to him or someone was looking for him."
At the time, Police Chief Lee Vance said residents were left reeling by the "shocking, brutal, bizarre" murder, which left "gaping wounds in the psyche of this city".
Me and my family, we just feel like we don't understand how something of this magnitude could have happened and you don't have any kind of information on it. Somebody had to see something.
Corey Jackson, Jeremy's brother "Me and my family, we just feel like we don't understand how something of this magnitude could have happened and you don't have any kind of information on it," he told the Ledger.
"Somebody had to see something."
Jackson police put out a reward for $20,000 or information at the time, but no arrests have been made.
However, Police Sergeant Roderick Holmes recently said the investigation was "ongoing". Investigators have identified persons of interest and "certain information is still being analysed, he said.
Erica Hutton, CEO of Hutton Forensics, a crime profiling agency, said the clean cut indicated a prolific criminal.
"This is not their first crime," she said. "This is not their first time killing... It's a message."
Jeremy Jackson was a student and had just been offered a job in a restaurant Police on the scene in Jackson, Mississippi