Keltner was transported to a nearby hospital where he later succumbed to his injuries.
According to
WPTA-TV
, Governor Jay Robert Pritzker said on Twitter, "The people of Illinois join the family of the fallen officer in mourning his loss, and with our deepest gratitude for his courageous service."
The sheriff said on Facebook, "For those of us in the McHenry County Sheriff’s Office, this is bitter news. Deputy Keltner was an integral part of our office, someone who had risen quickly to greater responsibilities after he was first sworn in in 2006. He was loved and respected by all his colleagues, and he will be sorely missed.
"I would like to take this opportunity to note the overwhelming support our Office has received from law enforcement at the federal, state and local level. Other Sheriff’s Offices, such as Winnebago County and DuPage County, have stood by us as the tragic events of this morning unfolded, and throughout this afternoon, and I am sure they will continue to do so."
Following the shooting, Brown fled the scene and led police on a high-speed vehicle pursuit. When the pursuit ended, Brown remained barricaded in his vehicle. Brown was later taken into custody.
Keltner had served with the McHenry County Sheriff's Office for 13 years.