The Newton County Sheriff's Office said on Facebook that Cpl. Brandon Schreiber died Wednesday morning.
Schreiber was shot last week after pursuing an armed suspect with a suspected hostage from Illinois. An officer shot and killed that suspect, identified as 37-year-old Andrew Roselius.
Police did not find a hostage inside Roselius' vehicle. Illinois State Police are investigating the shootout.
Schreiber was an organ donor, and the department said his sacrifice in the line of duty will help save others.
He was a five-year veteran with the Newton County Sheriff's Office.
Schreiber's body will be escorted from Springfield Thursday morning.
His funeral arrangements have not yet been released.